1
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Suzuki M, Funasaka N, Sato Y, Inamori D, Watanabe Y, Ozaki M, Hosono M, Shindo H, Kawamura K, Tatsukawa T, Yoshioka M. Association of seasonal changes in circulating cortisol concentrations with the expression of cortisol biosynthetic enzymes and a glucocorticoid receptor in the blubber of common bottlenose dolphin. Gen Comp Endocrinol 2024; 352:114516. [PMID: 38593942 DOI: 10.1016/j.ygcen.2024.114516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 03/15/2024] [Accepted: 04/06/2024] [Indexed: 04/11/2024]
Abstract
Cortisol is secreted from the adrenal cortex in response to stress, and its circulating levels are used as robust physiological indicators of stress intensity in various animals. Cortisol is also produced locally in adipose tissue by the conversion of steroid hormones such as cortisone, which is related to fat accumulation. Circulating cortisol levels, probably induced by cold stress, increase in cetaceans under cold conditions. However, whether cortisol production in subcutaneous adipose tissue is enhanced when fat accumulation is renewed during the cold season remains unclear. Therefore, in this study, we examine the effect of environmental temperature on the expression of cortisol synthesis-related enzymes and a glucocorticoid receptor in the subcutaneous fat (blubber) and explore the association between these expressions and fluctuations in circulating cortisol levels in common bottlenose dolphins (Tursiops truncatus). Skin biopsies were obtained seasonally from eight female dolphins, and seasonal differences in the expression of target genes in the blubber were analyzed. Blood samples were collected throughout the year, and cortisol levels were measured. We found that the expressions of cytochrome P450 family 21 subfamily A member 2 (CYP21A2) and nuclear receptor subfamily 3 group C member 1 (NR3C1), a glucocorticoid receptor, were increased in the cold season, and 11 beta-hydroxysteroid dehydrogenase type 1 (HSD11B1) showed a similar trend. Blood cortisol levels increased when the water temperature decreased. These results suggest that the conversion of 17-hydroxyprogesterone to cortisol via 11-deoxycortisol and/or of cortisone to cortisol is enhanced under cold conditions, and the physiological effects of cortisol in subcutaneous adipose tissue may contribute to on-site lipid accumulation and increase the circulating cortisol concentrations. The results obtained in this study highlight the role of cortisol in the regulation of the blubber that has developed to adapt to aquatic life.
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Affiliation(s)
- Miwa Suzuki
- College of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
| | - Noriko Funasaka
- Cetacean Research Center, Graduate School of Bioresources, Mie University, Tsu, Mie 514-8507 Japan
| | - Yuki Sato
- College of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Daiki Inamori
- Taiji Whale Museum, Higashimuro, Wakayama 649-5171 Japan
| | - Yurie Watanabe
- Taiji Whale Museum, Higashimuro, Wakayama 649-5171 Japan
| | - Miki Ozaki
- Adventure World, Nishimuro, Wakayama 649-2201 Japan
| | | | - Hideaki Shindo
- Shimonoseki Marine Science Museum, Shimonoseki, Yamaguchi 750-0036 Japan
| | - Keiko Kawamura
- Shimonoseki Marine Science Museum, Shimonoseki, Yamaguchi 750-0036 Japan
| | | | - Motoi Yoshioka
- Cetacean Research Center, Graduate School of Bioresources, Mie University, Tsu, Mie 514-8507 Japan.
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2
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Agustí C, Manteca X, García-Párraga D, Tallo-Parra O. Validating a Non-Invasive Method for Assessing Cortisol Concentrations in Scraped Epidermal Skin from Common Bottlenose Dolphins and Belugas. Animals (Basel) 2024; 14:1377. [PMID: 38731382 PMCID: PMC11083227 DOI: 10.3390/ani14091377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 04/13/2024] [Accepted: 04/30/2024] [Indexed: 05/13/2024] Open
Abstract
Society is showing a growing concern about the welfare of cetaceans in captivity as well as cetaceans in the wild threatened by anthropogenic disturbances. The study of the physiological stress response is increasingly being used to address cetacean conservation and welfare issues. Within it, a newly described technique of extracting cortisol from epidermal desquamation may serve as a non-invasive, more integrated measure of a cetacean's stress response and welfare. However, confounding factors are common when measuring glucocorticoid hormones. In this study, we validated a steroid hormone extraction protocol and the use of a commercial enzyme immunoassay (EIA) test to measure cortisol concentrations in common bottlenose dolphin (Tursiops truncatus) and beluga (Delphinapterus leucas) epidermal samples. Moreover, we examined the effect of sample mass and body location on cortisol concentrations. Validation tests (i.e., assay specificity, accuracy, precision, and sensitivity) suggested that the method was suitable for the quantification of cortisol concentrations. Cortisol was extracted from small samples (0.01 g), but the amount of cortisol detected and the variability between duplicate extractions increased as the sample mass decreased. In common bottlenose dolphins, epidermal skin cortisol concentrations did not vary significantly across body locations while there was a significant effect of the individual. Overall, we present a contribution towards advancing and standardizing epidermis hormone assessments in cetaceans.
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Affiliation(s)
- Clara Agustí
- Animal Welfare Education Centre (AWEC), School of Veterinary Science, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain; (X.M.); (O.T.-P.)
| | - Xavier Manteca
- Animal Welfare Education Centre (AWEC), School of Veterinary Science, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain; (X.M.); (O.T.-P.)
| | - Daniel García-Párraga
- Fundación Oceanogràfic de la Comunitat Valenciana, Research Department, Ciudad de las Artes y las Ciencias, 46013 Valencia, Spain;
| | - Oriol Tallo-Parra
- Animal Welfare Education Centre (AWEC), School of Veterinary Science, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain; (X.M.); (O.T.-P.)
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3
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Cha J, Hong S, Lee J, Gwak J, Kim M, Mok S, Moon HB, Jones PD, Giesy JP, Khim JS. Identification of Mid-Polar and Polar AhR Agonists in Cetaceans from Korean Coastal Waters: Application of Effect-Directed Analysis with Full-Scan Screening. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:15644-15655. [PMID: 37787753 PMCID: PMC10586376 DOI: 10.1021/acs.est.3c04311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/16/2023] [Accepted: 09/18/2023] [Indexed: 10/04/2023]
Abstract
Major aryl hydrocarbon receptor (AhR) agonists were identified in extracts of blubber, liver, and muscle from six long-beaked common dolphins (Delphinus capensis) and one fin whale (Balaenoptera physalus) collected from Korean coastal waters using effect-directed analysis. Results of the H4IIE-luc bioassay indicated that the polar fractions of blubber and liver extracts from the fin whale exhibited relatively high AhR-mediated potencies. Based on full-scan screening with high-resolution mass spectrometry, 37 AhR agonist candidates, spanning four use categories: pharmaceuticals, pesticides, cosmetics, and natural products, were selected. Among these, five polar AhR agonists were newly identified through toxicological confirmation. Concentrations of polar AhR agonists in cetaceans were tissue-specific, with extracts of blubber and liver containing greater concentrations than muscle extracts. Polar AhR agonists with great log KOA values (>5) were found to biomagnify in the marine food chain potentially. Polar AhR agonists contributed 8.9% of the observed AhR-mediated potencies in blubber and 49% in liver. Rutaecarpine and alantolactone contributed significantly to the total AhR-mediated potencies of blubber, whereas hydrocortisone was a major AhR contributor in the liver of the fin whale. This study is the first to identify the tissue-specific accumulation of polar AhR agonists in blubber and liver extracts of cetaceans.
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Affiliation(s)
- Jihyun Cha
- Department
of Marine Environmental Science, Chungnam
National University, Daejeon 34134, Republic
of Korea
| | - Seongjin Hong
- Department
of Marine Environmental Science, Chungnam
National University, Daejeon 34134, Republic
of Korea
| | - Junghyun Lee
- School
of Earth and Environmental Sciences & Research Institute of Oceanography, Seoul National University, Seoul 08826, Republic of Korea
- Department
of Environmental Education, Kongju National
University, Gongju 32588, Republic of Korea
| | - Jiyun Gwak
- Department
of Marine Environmental Science, Chungnam
National University, Daejeon 34134, Republic
of Korea
| | - Mungi Kim
- Department
of Marine Environmental Science, Chungnam
National University, Daejeon 34134, Republic
of Korea
| | - Sori Mok
- Department
of Marine Science and Convergence Engineering, Hanyang University, Ansan 15588, Republic
of Korea
| | - Hyo-Bang Moon
- Department
of Marine Science and Convergence Engineering, Hanyang University, Ansan 15588, Republic
of Korea
| | - Paul D. Jones
- Department
of Veterinary Biomedical Sciences & Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan S7N5B3, Canada
| | - John P. Giesy
- Department
of Veterinary Biomedical Sciences & Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan S7N5B3, Canada
- Department
of Integrative Biology and Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan 48824, United States
- Department
of Environmental Science, Baylor University, Waco, Texas 76798-7266, United States
| | - Jong Seong Khim
- School
of Earth and Environmental Sciences & Research Institute of Oceanography, Seoul National University, Seoul 08826, Republic of Korea
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4
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Renaud LA, Bordeleau X, Kellar NM, Pigeon G, Michaud R, Morin Y, Lair S, Therien A, Lesage V. Estimating pregnancy rate from blubber progesterone levels of a blindly biopsied beluga population poses methodological, analytical and statistical challenges. CONSERVATION PHYSIOLOGY 2023; 11:coad075. [PMID: 37771677 PMCID: PMC10533324 DOI: 10.1093/conphys/coad075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 07/13/2023] [Accepted: 09/06/2023] [Indexed: 09/30/2023]
Abstract
Beluga (Delphinapterus leucas) from the St. Lawrence Estuary, Canada, have been declining since the early 2000s, suggesting recruitment issues as a result of low fecundity, abnormal abortion rates or poor calf or juvenile survival. Pregnancy is difficult to observe in cetaceans, making the ground truthing of pregnancy estimates in wild individuals challenging. Blubber progesterone concentrations were contrasted among 62 SLE beluga with a known reproductive state (i.e. pregnant, resting, parturient and lactating females), that were found dead in 1997 to 2019. The suitability of a threshold obtained from decaying carcasses to assess reproductive state and pregnancy rate of freshly-dead or free-ranging and blindly-sampled beluga was examined using three statistical approaches and two data sets (135 freshly harvested carcasses in Nunavik, and 65 biopsy-sampled SLE beluga). Progesterone concentrations in decaying carcasses were considerably higher in known-pregnant (mean ± sd: 365 ± 244 ng g-1 of tissue) than resting (3.1 ± 4.5 ng g-1 of tissue) or lactating (38.4 ± 100 ng g-1 of tissue) females. An approach based on statistical mixtures of distributions and a logistic regression were compared to the commonly-used, fixed threshold approach (here, 100 ng g-1) for discriminating pregnant from non-pregnant females. The error rate for classifying individuals of known reproductive status was the lowest for the fixed threshold and logistic regression approaches, but the mixture approach required limited a priori knowledge for clustering individuals of unknown pregnancy status. Mismatches in assignations occurred at lipid content < 10% of sample weight. Our results emphasize the importance of reporting lipid contents and progesterone concentrations in both units (ng g-1 of tissue and ng g-1 of lipid) when sample mass is low. By highlighting ways to circumvent potential biases in field sampling associated with capturability of different segments of a population, this study also enhances the usefulness of the technique for estimating pregnancy rate of free-ranging population.
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Affiliation(s)
- L -A Renaud
- Department of Fisheries and Oceans Canada, Maurice Lamontagne Institute, P.O. Box 1000, 850 Route de la Mer, Mont-Joli, Québec, G5H 3Z4, Canada
| | - X Bordeleau
- Department of Fisheries and Oceans Canada, Maurice Lamontagne Institute, P.O. Box 1000, 850 Route de la Mer, Mont-Joli, Québec, G5H 3Z4, Canada
| | - N M Kellar
- Southwest Fisheries Science Center, National Marine Fisheries Service, P.O. Box 271, La Jolla, California 92038, USA
| | - G Pigeon
- Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, Québec, J9X 5E4, Canada
| | - R Michaud
- Groupe de recherche et d’éducation sur les mammifères marins (GREMM), 108 de la Cale-Sèche, Tadoussac, Québec, G0T 2A0, Canada
| | - Y Morin
- Department of Fisheries and Oceans Canada, Maurice Lamontagne Institute, P.O. Box 1000, 850 Route de la Mer, Mont-Joli, Québec, G5H 3Z4, Canada
| | - S Lair
- Faculté de médecine vétérinaire, Université de Montréal, P.O. Box 5000, 3200 Rue Sicotte, St-Hyacinthe, Québec, J2S 7C6, Canada
| | - A Therien
- Department of Fisheries and Oceans Canada, Maurice Lamontagne Institute, P.O. Box 1000, 850 Route de la Mer, Mont-Joli, Québec, G5H 3Z4, Canada
| | - V Lesage
- Department of Fisheries and Oceans Canada, Maurice Lamontagne Institute, P.O. Box 1000, 850 Route de la Mer, Mont-Joli, Québec, G5H 3Z4, Canada
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5
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Lysiak NSJ, Ferguson SH, Hornby CA, Heide-Jørgensen MP, Matthews CJD. Prolonged baleen hormone cycles suggest atypical reproductive endocrinology of female bowhead whales. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230365. [PMID: 37501659 PMCID: PMC10369022 DOI: 10.1098/rsos.230365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 07/05/2023] [Indexed: 07/29/2023]
Abstract
Serial measurements of hormone concentrations along baleen plates allow for reconstructions of mysticete whale reproductive histories. We assessed gestation and calving interval in bowhead whales (Balaena mysticetus) by measuring progesterone, oestradiol, corticosterone and nitrogen stable isotope ratios (δ15N) along baleen of 10 females from the eastern Canada-west Greenland population. Three immature females (body size < 14.32 m) had uniformly low progesterone concentrations across their baleen, while seven mature females (body size ≥ 14.35 m) had repeated, sustained elevations of progesterone indicative of pregnancies. The mean duration of progesterone elevations (23.6 ± 1.50 months) was considerably longer than the approximately 14 month gestation previously estimated for this species. We consider several possible explanations for this observation, including delayed implantation or sequential ovulations prior to gestation, strategies that would allow females to maximize their fitness in variable Arctic conditions, as well as suggest modified criteria defining gestation as a shorter component of the entire progesterone peak. Calving intervals varied within and among individuals (mean = 3.7 years; range = range 2.8-5.7 years), providing population-specific reproductive estimates for growth models used in bowhead whale management and conservation.
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Affiliation(s)
- N. S. J. Lysiak
- Biology Department, Suffolk University, Boston, 02108, MA, USA
| | - S. H. Ferguson
- Arctic Aquatic Research Division, Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, Manitoba, Canada R3T 2N6
| | - C. A. Hornby
- Arctic Aquatic Research Division, Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, Manitoba, Canada R3T 2N6
| | | | - C. J. D. Matthews
- Arctic Aquatic Research Division, Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, Manitoba, Canada R3T 2N6
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6
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Wong CH, Tsai MA, Ko FC, Wang JH, Xue YJ, Yang WC. Skin Cortisol and Acoustic Activity: Potential Tools to Evaluate Stress and Welfare in Captive Cetaceans. Animals (Basel) 2023; 13:ani13091521. [PMID: 37174558 PMCID: PMC10177183 DOI: 10.3390/ani13091521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/05/2023] [Accepted: 04/26/2023] [Indexed: 05/15/2023] Open
Abstract
As people's focus broadens from animals on farms to zoos and aquaria, the field of welfare science and the public's concern for animal welfare continue to grow. In captive animals, stress and its causes are topics of interest in welfare issues, and the identification of an objective method that can be used to assess animals' stress as a physiological state is essential. Both behavioral and physiological parameters can be used as indicators in order to assess animal stress quantitatively. To validate this approach, acoustic activity and the sloughed scrape skin cortisol concentration were used to evaluate the animal welfare of captive beluga whales (Delphinapterus leucas). The acoustic activity (5 min at 10:00 am) of three captive D. leucas was routinely recorded by a transducer and analyzed using audio editing software. The calls were separated into three main categories: whistles, pulses, and combo calls. The sloughed scrape skin samples were collected non-invasively once a week from all three animals' fluke and/or flipper. Cortisol was extracted using a modified skin steroid extraction technique, and detected via commercially available enzyme immunoassays. The results showed that the cortisol concentration increased by varying levels when the whales encountered the same event. In addition, the number and distribution of the calls changed along with the events. This indicated that the changes in the cortisol concentration and acoustic behavior may have reflected the fluctuations in the environment and body condition. Therefore, the scrape cortisol measurement and acoustic recordings could be used to monitor stress levels in captive beluga whales. We recommend that aquaria consider incorporating skin scrape cortisol and acoustic activity monitoring into their standards for animal welfare.
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Affiliation(s)
- Chung-Hei Wong
- School of Veterinary Medicine, National Taiwan University, Taipei 106, Taiwan
| | - Ming-An Tsai
- Collage of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 912, Taiwan
- National Museum of Marine Biology and Aquarium, Pingtung 944, Taiwan
| | - Fung-Chi Ko
- National Museum of Marine Biology and Aquarium, Pingtung 944, Taiwan
- Institute of Marine Biology, National Dong-Hwa University, Pingtung 944, Taiwan
| | - Jiann-Hsiung Wang
- College of Veterinary Medicine, National Chiayi University, Chiayi 600, Taiwan
| | - Yi-Jing Xue
- College of Veterinary Medicine, National Chiayi University, Chiayi 600, Taiwan
| | - Wei-Cheng Yang
- School of Veterinary Medicine, National Taiwan University, Taipei 106, Taiwan
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7
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Guo Y, Shi W, Liu Z, Sun X, Wu J, Wu Y. Bisphenol A alternatives continuously contribute to the endocrine disruption in cetaceans. ENVIRONMENT INTERNATIONAL 2023; 171:107679. [PMID: 36493609 DOI: 10.1016/j.envint.2022.107679] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 12/01/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
The bans on bisphenol A (BPA) have facilitated the widespread use of BPA alternatives and shifted environmental contamination profiles of bisphenols (BPs). However, the continued reports of toxicities of emerging BPA alternatives have raised questions about whether the shifting profiles are contributed to mitigate BPs-mediated endocrine-disruption effects (EDEs). Cetaceans are commonly used as the ideal sentinel species for monitoring marine pollutants of concern and determining potential health effects, but far less is known about BP loads and BPs-mediated EDEs in cetaceans. Here we measured the hepatic concentrations of six BPs in eight stranded cetacean species (n = 41) in the South China Sea, between 2007 and 2020. The large-bodied whales generally showed higher ∑BPs concentrations than the small-bodied dolphins. In Indo-Pacific finless porpoises (Neophocaena phocaenoides) (n = 33), BPA concentrations first increased (2007-2014) and then decreased (2014-2020), while ∑BPAlternatives concentrations increased from 2007 to 2020. It appears that the alternatives gradually replaced BPA, probably due to the BPA-related bans in China. In order to examine the hormone disruption of BPA and its alternatives in finless porpoises, five blubber hormones (cortisol, progesterone, testosterone, triiodothyronine and tetraiodothyronine), which are proven to be validated endocrine biomarkers, were measured in 21 samples. Tetraiodothyronine, testosterone, and cortisol were significantly and positively correlated with BPA and its alternatives, suggesting that the interference of endocrine hormone homeostasis may continue to occur despite the changes of BP profiles in finless porpoises. This is the first investigation of the relationship between hormone and BP concentrations in cetaceans and represents a substantial advance in understanding BPs-mediated endocrine effects on cetaceans.
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Affiliation(s)
- Yongwei Guo
- School of Marine Sciences, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Pearl River Estuary Marine Ecosystem Research Station, Ministry of Education, Sun Yat-Sen University, Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai 519082, China
| | - Wei Shi
- School of Marine Sciences, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Pearl River Estuary Marine Ecosystem Research Station, Ministry of Education, Sun Yat-Sen University, Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai 519082, China
| | - Zhiwei Liu
- School of Ecology, Sun Yat-sen University, Guangzhou 510275, China
| | - Xian Sun
- School of Marine Sciences, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Pearl River Estuary Marine Ecosystem Research Station, Ministry of Education, Sun Yat-Sen University, Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai 519082, China.
| | - Jiaxue Wu
- School of Marine Sciences, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Pearl River Estuary Marine Ecosystem Research Station, Ministry of Education, Sun Yat-Sen University, Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai 519082, China
| | - Yuping Wu
- School of Marine Sciences, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Pearl River Estuary Marine Ecosystem Research Station, Ministry of Education, Sun Yat-Sen University, Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai 519082, China
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8
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Pallin LJ, Botero-Acosta N, Steel D, Baker CS, Casey C, Costa DP, Goldbogen JA, Johnston DW, Kellar NM, Modest M, Nichols R, Roberts D, Roberts M, Savenko O, Friedlaender AS. Variation in blubber cortisol levels in a recovering humpback whale population inhabiting a rapidly changing environment. Sci Rep 2022; 12:20250. [PMID: 36424421 PMCID: PMC9686265 DOI: 10.1038/s41598-022-24704-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 11/18/2022] [Indexed: 11/27/2022] Open
Abstract
Glucocorticoids are regularly used as biomarkers of relative health for individuals and populations. Around the Western Antarctic Peninsula (WAP), baleen whales have and continue to experience threats, including commercial harvest, prey limitations and habitat change driven by rapid warming, and increased human presence via ecotourism. Here, we measured demographic variation and differences across the foraging season in blubber cortisol levels of humpback whales (Megaptera novaeangliae) over two years around the WAP. Cortisol concentrations were determined from 305 biopsy samples of unique individuals. We found no significant difference in the cortisol concentration between male and female whales. However, we observed significant differences across demographic groups of females and a significant decrease in the population across the feeding season. We also assessed whether COVID-19-related reductions in tourism in 2021 along the WAP correlated with lower cortisol levels across the population. The decline in vessel presence in 2021 was associated with a significant decrease in humpback whale blubber cortisol concentrations at the population level. Our findings provide critical contextual data on how these hormones vary naturally in a population over time, show direct associations between cortisol levels and human presence, and will enable comparisons among species experiencing different levels of human disturbance.
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Affiliation(s)
- L. J. Pallin
- grid.205975.c0000 0001 0740 6917Present Address: Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA 95060 USA
| | - N. Botero-Acosta
- Fundación Macuáticos Colombia, Calle 27 # 79-167, Medellín, Colombia ,Programa Antártico Colombiano, Avenida Ciudad de Cali #51 - 66, Oficina 306, Edificio World Business Center – WBC, Bogotá, D.C. Colombia
| | - D. Steel
- grid.4391.f0000 0001 2112 1969Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Hatfield Marine Science Center, 2030 SE Marine Science Drive, Newport, OR 97365 USA
| | - C. S. Baker
- grid.4391.f0000 0001 2112 1969Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Hatfield Marine Science Center, 2030 SE Marine Science Drive, Newport, OR 97365 USA
| | - C. Casey
- grid.205975.c0000 0001 0740 6917Institute for Marine Science, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA 95060 USA ,California Ocean Alliance, 9099 Soquel Ave, Aptos, CA 95003 USA
| | - D. P. Costa
- grid.205975.c0000 0001 0740 6917Present Address: Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA 95060 USA
| | - J. A. Goldbogen
- grid.168010.e0000000419368956Department of Biology, Hopkins Marine Station, Stanford University, 120 Ocean View Blvd, Pacific Grove, CA 93950 USA
| | - D. W. Johnston
- grid.26009.3d0000 0004 1936 7961Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University Marine Laboratory, 135 Duke Marine Lab Road, Beaufort, NC 28516 USA
| | - N. M. Kellar
- grid.422702.10000 0001 1356 4495Marine Mammal Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 8901 La Jolla Shores Drive, La Jolla, CA 92037 USA
| | - M. Modest
- grid.205975.c0000 0001 0740 6917Present Address: Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA 95060 USA
| | - R. Nichols
- grid.205975.c0000 0001 0740 6917Department of Ocean Sciences, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA 95060 USA
| | - D. Roberts
- California Ocean Alliance, 9099 Soquel Ave, Aptos, CA 95003 USA
| | - M. Roberts
- California Ocean Alliance, 9099 Soquel Ave, Aptos, CA 95003 USA
| | - O. Savenko
- National Antarctic Scientific Center of Ukraine, 16 Taras Shevchenko Blvd., Kyiv, 01601 Ukraine ,grid.438834.0Ukrainian Scientific Center of Ecology of the Sea, 89 Frantsuzsky Blvd., Odesa, 65009 Ukraine
| | - A. S. Friedlaender
- California Ocean Alliance, 9099 Soquel Ave, Aptos, CA 95003 USA ,grid.205975.c0000 0001 0740 6917Department of Ocean Sciences, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA 95060 USA
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9
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Melica V, Atkinson S, Calambokidis J, Gendron D, Lang A, Scordino J. Naturally stressed? Glucocorticoid profiles in blubber of blue and gray whales in response to life history parameters. MARINE MAMMAL SCIENCE 2022; 38:1524-1548. [PMID: 36619002 PMCID: PMC9815209 DOI: 10.1111/mms.12954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The goal of the present study was to carry out a thorough methodological validation and describe baseline profiles for glucocorticoid hormones (cortisol and corticosterone) in blubber from blue (n = 77) and gray (n = 103) whales from the eastern North Pacific Ocean. For each species, we modelled cortisol and corticosterone concentrations in response to life history parameters (age, sex, reproductive status) and season or geographic location. In blue whales, cortisol concentrations did not vary significantly by age class, sex, or reproductive status, whereas corticosterone was significantly lower in immature than in adult females (p < .001). In gray whales, cortisol concentrations were significantly higher in lactating whales (p < .05), while corticosterone was significantly different between females and males (p = .001) and elevated in calves (p = .003). In gray whales, corticosterone concentrations were significantly lower in males sampled later in the year (August to November) compared to both sexes sampled between March and August (p = .05), but no seasonal trend occurred in blue whales. Our results indicate that glucocorticoid actions vary between species and sex in large whales. Analysis of multiple hormones improves our understanding of the physiology of maintaining metabolic homeostasis or coping with chronic stressors.
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Affiliation(s)
- Valentina Melica
- Fisheries Department, College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, Alaska
| | - Shannon Atkinson
- Fisheries Department, College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, Alaska
| | | | - Diane Gendron
- Instituto Politecnico Nacional, Centro Interdisciplinario de Ciencias Marina (IPN-CICIMAR), La Paz, Baja California Sur, Mexico
| | - Aimee Lang
- Ocean Associates Inc., on contract to NOAA Southwest Fisheries Science Center, La Jolla, California
| | - Jonathan Scordino
- Marine Mammal Program, Makah Fisheries Management, Neah Bay, Washington
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10
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Agusti C, Carbajal A, Olvera-Maneu S, Domingo M, Lopez-Bejar M. Blubber and serum cortisol concentrations as indicators of the stress response and overall health status in striped dolphins. Comp Biochem Physiol A Mol Integr Physiol 2022; 272:111268. [PMID: 35817193 DOI: 10.1016/j.cbpa.2022.111268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 07/04/2022] [Accepted: 07/05/2022] [Indexed: 11/30/2022]
Abstract
The impacts of environmental changes and anthropogenic threats in marine mammals are a growing concern for their conservation. In recent years, efforts have been directed to understand how marine mammals cope with stressors and to assess and validate stress biomarkers, mainly levels of glucocorticoid hormones (e.g. cortisol) in certain body tissues. The aims of this study were to assess the impact of different causes of stranding (chronically affected and bycaught striped dolphins) on cortisol concentrations in serum and in blubber; and to evaluate the association between cortisol levels in these tissues. Blubber and blood samples were collected from striped dolphins (n = 42) stranded on the Mediterranean coast between 2012 and 2018. Cortisol concentrations were measured by using enzyme immunoassay. A high correlation was found between circulating and blubber cortisol concentrations (R2 = 0.85, p < 0.01). Necropsies and pathological studies concluded that a third of the dolphins were bycaught in fishing nets and released by fishermen (Bycaught animals group), while the other two thirds were euthanized, or died, due to a disease or chronic condition (e.g. calves separated from the mother or animals infected with dolphin morbillivirus or Brucella ceti) that impeded survival (Chronically affected animals group). Cortisol concentrations (mean ± SD) were six times higher in chronically affected animals (35.3 ± 23 ng cortisol/g blubber and 6.63 ± 3.22 μg cortisol/dl serum) compared to those bycaught in fishing nets (6.2 ± 4.3 ng cortisol/g blubber and 1.15 ± 1.51 μg cortisol/dl serum). Results suggests that serum and blubber cortisol concentrations can contribute in inferring the overall health and welfare of free-ranging cetaceans. However, further research is required to understand better the kinetics of blubber cortisol incorporation and removal, the factors involved in these processes, and the local conversion of cortisol in the blubber.
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Affiliation(s)
- Clara Agusti
- Zoo Animal Welfare Education Centre (ZAWEC), Veterinary Faculty, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
| | - Annaïs Carbajal
- Department of Animal Health and Anatomy, Veterinary Faculty, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Sergi Olvera-Maneu
- Department of Animal Health and Anatomy, Veterinary Faculty, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Mariano Domingo
- Department of Animal Health and Anatomy, Veterinary Faculty, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain; CRESA (Centre de Recerca en Sanitat Animal), Campus Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Barcelona, Spain
| | - Manel Lopez-Bejar
- Department of Animal Health and Anatomy, Veterinary Faculty, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain; College of Veterinary Medicine, Western University of Health Sciences, Pomona 91766, CA, USA
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11
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Guo Y, Gui D, Zhang X, Liu W, Xie Q, Yu X, Wu Y. Blubber Cortisol-Based Approach to Explore the Endocrine Responses of Indo-Pacific Humpback Dolphins ( Sousa chinensis) to Diet Shifts and Contaminant Exposure. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:1069-1080. [PMID: 34965107 DOI: 10.1021/acs.est.1c04550] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The detrimental effects of contaminant exposure and changes in the availability of food resources are still of concern for Indo-Pacific humpback dolphins (Sousa chinensis) of the Pearl River Estuary (PRE). Here, we validated and applied a blubber cortisol biomarker approach to assess the physiological responses of PRE dolphins to various pollutants and diet changes during 2008-2018 (n = 70). For calves, generalized additive models (GAMs) revealed that cortisol levels varied significantly by month and were positively correlated with the body length, owing to significant maternal transfer of hormones. The significantly positive correlation between length-adjusted cortisol levels in calf and the annual calf mortality ratios suggested that during years of high calf mortality, these animals were highly stressed before they die. For noncalves, blubber cortisol levels in diseased animals were significantly higher than those in "healthy" ones. Chromium (Cr) and dichlorodiphenyltrichloroethanes displayed a significant and positive relationship with blubber cortisol levels, suggesting that contaminant-mediated endocrine disruption effects may have occurred in noncalves. The GAMs indicated a decreasing trend of noncalf's blubber cortisol levels over an 11-year span, which can be explained by their declining contaminant accumulation levels due to a significant dietary shift from eating highly contaminated fishes to less polluted ones.
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Affiliation(s)
- Yongwei Guo
- School of Marine Sciences, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Pearl River Estuary Marine Ecosystem Research Station, Ministry of Education, Sun Yat-Sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China
| | - Duan Gui
- School of Marine Sciences, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Pearl River Estuary Marine Ecosystem Research Station, Ministry of Education, Sun Yat-Sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China
| | - Xiyang Zhang
- School of Marine Sciences, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Pearl River Estuary Marine Ecosystem Research Station, Ministry of Education, Sun Yat-Sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China
| | - Wen Liu
- School of Marine Sciences, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Pearl River Estuary Marine Ecosystem Research Station, Ministry of Education, Sun Yat-Sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China
| | - Qiang Xie
- School of Marine Sciences, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Pearl River Estuary Marine Ecosystem Research Station, Ministry of Education, Sun Yat-Sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China
| | - Xinjian Yu
- School of Marine Sciences, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Pearl River Estuary Marine Ecosystem Research Station, Ministry of Education, Sun Yat-Sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China
| | - Yuping Wu
- School of Marine Sciences, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Pearl River Estuary Marine Ecosystem Research Station, Ministry of Education, Sun Yat-Sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China
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12
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Houser DS, Champagne CD, Wasser SK, Booth RK, Romano T, Crocker DE. Influence of season, age, sex, and time of day on the endocrine profile of the common bottlenose dolphin (Tursiops truncatus). Gen Comp Endocrinol 2021; 313:113889. [PMID: 34425086 DOI: 10.1016/j.ygcen.2021.113889] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 08/03/2021] [Accepted: 08/18/2021] [Indexed: 01/15/2023]
Abstract
Understanding baseline hormone levels, the magnitude of intra-individual variability, and their variation as a function of life history is difficult in toothed whales (e.g. dolphins and porpoises) because of the effects of capture stress. To determine the endocrine profile of the common bottlenose dolphin (Tursiops truncatus) as a function of season, time of day (TOD), age, sex, and reproductive status, blood corticosteroids, thyroid hormones, and catecholamines were repeatedly measured in a managed-care population exposed to ambient light and water temperatures of San Diego Bay. Additionally, fecal hormone metabolites were assessed for cortisol, aldosterone, and triiodothyronine. Samples were collected at two to four-week intervals over a period of two years, and multiple times within a day at monthly intervals over a year. Samples were collected through the voluntary participation of the dolphins in the blood draws and fecal collections in order to avoid the effects of handling stress. All serum hormones except aldosterone significantly varied with season and all serum hormones except total thyroxine significantly varied as a function of TOD. Fecal glucocorticoid metabolites significantly correlated with circulating cortisol levels, and there was a significant seasonal effect on triiodothyronine fecal metabolites. Strong seasonal effects demonstrated complex interactions with age and sex suggesting that contextual information is critical to interpreting differences in endocrine profiles. Strong circadian patterns further suggest that sampling design is important to the interpretation of blood or fecal collections, particularly since diurnal changes in some serum hormone levels are similar to the magnitude of seasonal differences. Despite potential impacts of feeding schedules on diurnal patterns, managed care populations can provide important insights into seasonal and age-related endocrine changes in toothed whales.
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Affiliation(s)
- D S Houser
- National Marine Mammal Foundation, 2240 Shelter Island Drive, Suite 200, San Diego, CA 92106, USA.
| | - C D Champagne
- National Marine Mammal Foundation, 2240 Shelter Island Drive, Suite 200, San Diego, CA 92106, USA
| | - S K Wasser
- Center for Conservation Biology, Box 351800, University of Washington, Seattle, WA 98195, USA
| | - R K Booth
- Center for Conservation Biology, Box 351800, University of Washington, Seattle, WA 98195, USA
| | - T Romano
- Mystic Aquarium, 55 Coogan Blvd, Mystic, CT 06355, USA
| | - D E Crocker
- Department of Biology, Sonoma State University, 1801 E. Cotati Ave, Rohnert Park, CA 94928, USA
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13
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Jacobs B, Rally H, Doyle C, O'Brien L, Tennison M, Marino L. Putative neural consequences of captivity for elephants and cetaceans. Rev Neurosci 2021; 33:439-465. [PMID: 34534428 DOI: 10.1515/revneuro-2021-0100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 09/02/2021] [Indexed: 12/20/2022]
Abstract
The present review assesses the potential neural impact of impoverished, captive environments on large-brained mammals, with a focus on elephants and cetaceans. These species share several characteristics, including being large, wide-ranging, long-lived, cognitively sophisticated, highly social, and large-brained mammals. Although the impact of the captive environment on physical and behavioral health has been well-documented, relatively little attention has been paid to the brain itself. Here, we explore the potential neural consequences of living in captive environments, with a focus on three levels: (1) The effects of environmental impoverishment/enrichment on the brain, emphasizing the negative neural consequences of the captive/impoverished environment; (2) the neural consequences of stress on the brain, with an emphasis on corticolimbic structures; and (3) the neural underpinnings of stereotypies, often observed in captive animals, underscoring dysregulation of the basal ganglia and associated circuitry. To this end, we provide a substantive hypothesis about the negative impact of captivity on the brains of large mammals (e.g., cetaceans and elephants) and how these neural consequences are related to documented evidence for compromised physical and psychological well-being.
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Affiliation(s)
- Bob Jacobs
- Laboratory of Quantitative Neuromorphology, Neuroscience Program, Colorado College, Colorado Springs, CO, 80903, USA
| | - Heather Rally
- Foundation to Support Animal Protection, Norfolk, VA, 23510, USA
| | - Catherine Doyle
- Performing Animal Welfare Society, P.O. Box 849, Galt, CA, 95632, USA
| | - Lester O'Brien
- Palladium Elephant Consulting Inc., 2408 Pinewood Dr. SE, Calgary, AB, T2B1S4, Canada
| | - Mackenzie Tennison
- Department of Psychology, University of Washington, Seattle, WA, 98195, USA
| | - Lori Marino
- Whale Sanctuary Project, Kanab, UT, 84741, USA
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14
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Melica V, Atkinson S, Gendron D, Calambokidis J, Mueter F. Blubber endocrine profiles provide insights into reproductive biology in blue whales from the eastern North Pacific Ocean. Gen Comp Endocrinol 2021; 310:113830. [PMID: 34087186 PMCID: PMC9167553 DOI: 10.1016/j.ygcen.2021.113830] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 05/26/2021] [Accepted: 05/31/2021] [Indexed: 01/07/2023]
Abstract
The goal of the present study was to complement existing data of testosterone and progesterone in blue whale (Balaenoptera musculus) blubber from the eastern North Pacific Ocean to evaluate effects of seasonality and location on these hormones and to better assess reproductive status of individuals. Physiological parameters regarding reproduction are fundamental for describing population dynamics, and hormones can be a valid tool to estimate those for wildlife populations. In this study, blubber tissue was validated for testosterone and progesterone assays. Hormone concentrations were measured in 69 (35 males and 34 females) blubber samples from live (n = 66) and stranded (n = 3) animals collected between 2002 and 2016 from a known winter reproductive ground in the Gulf of California (GoC) and summer feeding areas along the United States West Coast (USWC), specifically off the states of California and Oregon. Results were combined with sighting histories as a tool to determine reproductive status of individual whales. Testosterone concentrations in adult male blue whales were significantly higher (p < 0.05) in blubber biopsies sampled off the USWC between the months of June and November compared to those sampled in the GoC between February and April. Elevated testosterone concentrations likely indicate physiological preparation for reproductive activity while the animals were present off the USWC. Progesterone concentrations were significantly elevated in pregnant females, confirming progesterone as an indicator of pregnancy in blue whales. Probabilities of being pregnant were estimated for adult females with unknown sighting histories based on progesterone concentrations. Testosterone in females was detected and measured only in pregnant whales suggesting its biosynthesis or metabolism is altered during gestation. These results provide updated and new information on the reproductive cycle of blue whales in the eastern North Pacific, posing new milestones to better estimate the timing of the mating season for this endangered population.
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Affiliation(s)
- Valentina Melica
- University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Fisheries Dept, Juneau Center, 17101 Pt. Lena Loop Road, Juneau, AK 99801, USA.
| | - Shannon Atkinson
- University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Fisheries Dept, Juneau Center, 17101 Pt. Lena Loop Road, Juneau, AK 99801, USA.
| | - Diane Gendron
- Centro Interdisciplinario de Ciencias Marina (IPN-CICIMAR), Av. Instituto Politecnico Nacional s/n, playa Palo de Santa Rita, 23096 La Paz, B.C.S., Mexico
| | | | - Franz Mueter
- University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Fisheries Dept, Juneau Center, 17101 Pt. Lena Loop Road, Juneau, AK 99801, USA
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15
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Nabi G, Robeck TR, Yujiang H, Tang B, Zheng J, Wang K, Wang D. Circulating concentrations of thyroid hormones and cortisol in wild and semi-natural Yangtze finless porpoise ( Neophocaena asiaeorientalis). CONSERVATION PHYSIOLOGY 2021; 9:coab034. [PMID: 35559363 PMCID: PMC8120013 DOI: 10.1093/conphys/coab034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 03/15/2021] [Accepted: 04/21/2021] [Indexed: 06/15/2023]
Abstract
Our understanding about how environmental and biological variables may influence circulating thyroid and adrenal hormones in free-ranging cetaceans is limited. As such, we used liquid chromatography-mass spectrometry to determine concentrations of circulating cortisol and thyroid hormones (THs; tT3, tT4) in 132 Yangtze finless porpoises (YFPs) located in Poyang Lake, (PL, n = 92) and Tian-E-Zhou Oxbow reserve (TZO, n = 40). For overall hormone comparisons, animals were partitioned by age [juvenile and adult (male and non-pregnant, non-lactating female)], sex, season (winter or spring) and geographical location. Geographically, during winter, circulating THs were significantly higher in the PL versus TZO population. Seasonally, within PL, THs were significantly higher in the winter versus spring season. Animals were further binned into groups as follows: juvenile male (JM) and juvenile female (JF), adult male (AM), non-pregnant adult female, pregnant female and non-pregnant lactating female. Intra-group comparisons between locations showed a significant increase in JM THs at PL. Significant increases in THs during winter compared to spring were detected between JM and JF groups. Mean comparisons of cortisol within and between locations for each group identified a significant increase for TZO AM versus TZO pregnant female and JM and JF. Seasonally, in PL, only JF has significantly higher cortisol in winter versus spring. Finally, we established reference values of THs and cortisol for YFPs in different geographical locations. These references are important baselines from which the effects of environmental and biological variables on THs and cortisol may be evaluated.
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Affiliation(s)
- Ghulam Nabi
- The Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Science, Hebei Normal University, Shijiazhuang, 050024, China
| | | | - Hao Yujiang
- The Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Bin Tang
- The Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jinsong Zheng
- The Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Kexiong Wang
- The Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Ding Wang
- The Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
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16
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Sherman KK, Beaulieu-McCoy NE, Wurster EL, Wells RS, Smith CR, Barleycorn AA, Allen JB, Kellar NM. Serum correlation, demographic differentiation, and seasonality of blubber testosterone in common bottlenose dolphins, Tursiops truncatus, in Sarasota Bay, FL. Sci Rep 2021; 11:8941. [PMID: 33903714 PMCID: PMC8076180 DOI: 10.1038/s41598-021-88602-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 04/07/2021] [Indexed: 01/22/2023] Open
Abstract
Blubber and serum testosterone levels were compared among 55 individual common bottlenose dolphins, Tursiops truncatus, in Sarasota Bay, FL during 2011–2019. A significant positive relationship between the matrices was found in male testosterone concentrations in 29 paired samples (r2 = 0.932). Mature males (n = 17) had 300 times greater mean testosterone concentration in serum than immature males (n = 17). A comparison of blubber samples, including 12 females, 24 immature males, and 19 mature males, revealed significant differences in mean blubber testosterone values among all three demographics. Immature males had greater than 6 times the average blubber testosterone concentration of females and mature males had almost 100 times that of immature males. Estimated testis volume was highly correlated with blubber testosterone concentration and mature males had 60 times greater average testis volume than immature males. We observed seasonal variation in blubber testosterone in mature males, consistent with known reproductive patterns. These data suggest males can be distinguished from females and designated as mature or immature via blubber testosterone concentrations, an observation that validates dart biopsy sampling as a means of obtaining demographic data.
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Affiliation(s)
- Kathryn K Sherman
- Environmental Assessment Services, LLC, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 8901 La Jolla Shores Drive, La Jolla, CA, 92037, USA.
| | - Nicole E Beaulieu-McCoy
- Volunteer With Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 8901 La Jolla Shores Drive, La Jolla, CA, 92037, USA
| | - Elyse L Wurster
- Environmental Assessment Services, LLC, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 8901 La Jolla Shores Drive, La Jolla, CA, 92037, USA
| | - Randall S Wells
- Chicago Zoological Society's Sarasota Dolphin Research Program, c/o Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL, 34236, USA
| | - Cynthia R Smith
- National Marine Mammal Foundation, 2240 Shelter Island Drive, Suite 200, San Diego, CA, 92106, USA
| | - Aaron A Barleycorn
- Chicago Zoological Society's Sarasota Dolphin Research Program, c/o Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL, 34236, USA
| | - Jason B Allen
- Chicago Zoological Society's Sarasota Dolphin Research Program, c/o Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL, 34236, USA
| | - Nicholas M Kellar
- Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 8901 La Jolla Shores Drive, La Jolla, CA, 92037, USA
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17
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Graham KM, Burgess EA, Rolland RM. Stress and reproductive events detected in North Atlantic right whale blubber using a simplified hormone extraction protocol. CONSERVATION PHYSIOLOGY 2021; 9:coaa133. [PMID: 33489237 PMCID: PMC7808127 DOI: 10.1093/conphys/coaa133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 10/16/2020] [Accepted: 12/14/2020] [Indexed: 06/12/2023]
Abstract
As studies quantifying steroid hormones in marine mammal blubber progress, methodological refinements may improve the utility and consistency of blubber hormone measurements. This study advances blubber extraction methodologies by testing a simplified extraction protocol that reduces time and complexity compared to a protocol widely used in cetacean blubber studies. Using blubber samples archived from remote biopsy (n = 21 live whales) and necropsy collection (n = 7 dead whales) of North Atlantic right whales (NARW; Eubalaena glacialis) of known life history states, we performed analytical and biological validations to assess the feasibility of measuring reproductive (testosterone, progesterone) and glucocorticoid (cortisol) hormones in blubber via enzyme immunoassay following the simplified extraction. Analytical validations (parallelism, accuracy, extraction efficiency, repeatability) showed the simplified extraction produced similar results to the extended protocol, offering a more efficient and consistent technique. In live, apparently healthy whales, blubber testosterone concentrations (mean ± SE) were significantly higher in males (2.02 ± 0.36 ng/g) compared to females (0.81 ± 0.15 ng/g). Blubber progesterone was highest in a confirmed pregnant female (60.3 ng/g), which was 12-fold greater than the mean concentration of non-pregnant females (4.56 ± 0.88 ng/g). Blubber cortisol concentrations in whales that died from anthropogenic causes averaged 5.31 ± 2.28 ng/g, whereas most live, healthy whales had cortisol values below 1 ng/g. Among living whales, a whale actively entangled in fishing gear had the highest blubber cortisol measurement (3.51 ng/g), exhibiting levels similar to whales that died from acute entanglement (2.88 ± 0.42 ng/g). Overall, the highest blubber cortisol concentration (18.0 ng/g) was measured in a dead whale with a severe chronic entanglement, approximately 30-fold greater than mean blubber cortisol of apparently healthy whales (0.58 ± 0.11 ng/g). The methodological approach presented here provides a reference for researchers interested in an alternative, streamlined technique for hormone extraction of cetacean blubber and contributes to the diverse tool set for stress and reproductive assessments of endangered NARWs.
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Affiliation(s)
- Katherine M Graham
- Anderson Cabot Center for Ocean Life at the New England Aquarium, Central Wharf, Boston, MA 02110, USA
| | - Elizabeth A Burgess
- Anderson Cabot Center for Ocean Life at the New England Aquarium, Central Wharf, Boston, MA 02110, USA
| | - Rosalind M Rolland
- Anderson Cabot Center for Ocean Life at the New England Aquarium, Central Wharf, Boston, MA 02110, USA
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18
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Lowe CL, Hunt KE, Robbins J, Seton RE, Rogers M, Gabriele CM, Neilson JL, Landry S, Teerlink SS, Buck CL. Patterns of cortisol and corticosterone concentrations in humpback whale ( Megaptera novaeangliae) baleen are associated with different causes of death. CONSERVATION PHYSIOLOGY 2021; 9:coab096. [PMID: 34987826 PMCID: PMC8710851 DOI: 10.1093/conphys/coab096] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 10/08/2021] [Accepted: 12/06/2021] [Indexed: 05/15/2023]
Abstract
Baleen whales are subject to a myriad of natural and anthropogenic stressors, but understanding how these stressors affect physiology is difficult. Measurement of adrenal glucocorticoid (GC) hormones involved in the vertebrate stress response (cortisol and corticosterone) in baleen could help fill this data gap. Baleen analysis is a powerful tool, allowing for a retrospective re-creation of multiple years of GC hormone concentrations at approximately a monthly resolution. We hypothesized that whales that died from acute causes (e.g. ship strike) would have lower levels of baleen GCs than whales that died from extended illness or injury (e.g. long-term entanglement in fishing gear). To test this hypothesis, we extracted hormones from baleen plates of four humpback whales (Megaptera novaeangliae) with well-documented deaths including multiple and chronic entanglements (n = 1, female), ship strike (n = 2, male and female) and chronic illness with nutritional stress (n = 1, male). Over ~3 years of baleen growth and during multiple entanglements, the entangled whale had average corticosterone levels of 80-187% higher than the other three whales but cortisol levels were similar to two of the other three whales. The nutritionally stressed and chronically ill whale showed a slow increase in both cortisol and corticosterone spanning ~3 years, followed by a sharp decline in both hormones before death, possibly indicative of adrenal failure in this moribund individual. This whale's correlation between cortisol and corticosterone was significant but there were no correlations in the other three whales. Our results show that cortisol and corticosterone concentrations vary according to the type and duration of illness or injury. Single-point GC concentrations should be interpreted with caution as low values can occur in whales experiencing pronounced stress and individual baselines can be highly variable. Baleen analysis is a promising tissue type for retrospective analyses of physiological responses to various stressors affecting baleen whales.
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Affiliation(s)
- Carley L Lowe
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86001, USA
- Corresponding author: Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86001, USA. Tel: 702-524-3667. Fax: 928-523-7500.
| | - Kathleen E Hunt
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86001, USA
- Smithsonian-Mason School of Conservation & George Mason University, Front Royal, VA 22630, USA
| | - Jooke Robbins
- Center for Coastal Studies, Provincetown, MA 02657, USA
| | - Rosemary E Seton
- Allied Whale, College of the Atlantic, Bar Harbor, ME 04609, USA
| | - Matthew Rogers
- NOAA Fisheries, Alaska Fisheries Science Center Auke Bay Laboratories, Juneau, AK 99801, USA
| | | | - Janet L Neilson
- Glacier Bay National Park & Preserve, Gustavus, AK 99826, USA
| | - Scott Landry
- Center for Coastal Studies, Provincetown, MA 02657, USA
| | - Suzie S Teerlink
- NOAA Fisheries, Alaska Regional Office, Protected Resources Division, Juneau AK, 99801 USA
| | - C Loren Buck
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86001, USA
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19
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Crain DD, Thomas A, Mansouri F, Potter CW, Usenko S, Trumble SJ. Hormone comparison between right and left baleen whale earplugs. CONSERVATION PHYSIOLOGY 2020; 8:coaa055. [PMID: 32607240 PMCID: PMC7311829 DOI: 10.1093/conphys/coaa055] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 02/06/2020] [Accepted: 05/31/2020] [Indexed: 05/24/2023]
Abstract
Marine animals experience additional stressors as humans continue to industrialize the oceans and as the climate continues to rapidly change. To examine how the environment or humans impact animal stress, many researchers analyse hormones from biological matrices. Scientists have begun to examine hormones in continuously growing biological matrices, such as baleen whale earwax plugs, baleen and pinniped vibrissae. Few of these studies have determined if the hormones in these tissues across the body of the organism are interchangeable. Here, hormone values in the right and left earplugs from the same individual were compared for two reasons: (i) to determine whether right and left earplug hormone values can be used interchangeably and (ii) to assess methods of standardizing hormones in right and left earplugs to control for individuals' naturally varying hormone expressions. We analysed how absolute, baseline-corrected and Z-score normalized hormones performed in reaching these goals. Absolute hormones in the right and left earplugs displayed a positive relationship, while using Z-score normalization was necessary to standardize the variance in hormone expression. After Z-score normalization, it was possible to show that the 95% confidence intervals of the differences in corresponding lamina of the right and left earplugs include zero for both cortisol and progesterone. This indicates that the hormones in corresponding lamina of right and left earplugs are no different from zero. The results of this study reveal that both right and left earplugs from the same baleen whale can be used in hormone analyses after Z-score normalization. This study also shows the importance of Z-score normalization to interpretation of results and methodologies associated with analysing long-term trends using whale earplugs.
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Affiliation(s)
- Danielle D Crain
- Department of Biology, Baylor University, 101 Bagby Ave. Waco TX 76706, USA
| | - Amanda Thomas
- Department of Biology, Baylor University, 101 Bagby Ave. Waco TX 76706, USA
| | - Farzaneh Mansouri
- Department of Environmental Science, Baylor University, 101 Bagby Ave. Waco TX 76706, USA
| | - Charles W Potter
- Department of Vertebrate Zoology, Smithsonian Institution National Museum of Natural History, PO Box 37012 SI Bldg, Room 153, MRC 010, Washington, DC 20013 USA
| | - Sascha Usenko
- Department of Biology, Baylor University, 101 Bagby Ave. Waco TX 76706, USA
- Department of Environmental Science, Baylor University, 101 Bagby Ave. Waco TX 76706, USA
- Department of Chemistry and Biochemistry, Baylor University, 101 Bagby Ave. Waco TX 76706, USA
| | - Stephen J Trumble
- Department of Biology, Baylor University, 101 Bagby Ave. Waco TX 76706, USA
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20
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Mingramm FMJ, Keeley T, Whitworth DJ, Dunlop RA. Blubber cortisol levels in humpback whales (Megaptera novaeangliae): A measure of physiological stress without effects from sampling. Gen Comp Endocrinol 2020; 291:113436. [PMID: 32057910 DOI: 10.1016/j.ygcen.2020.113436] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 02/01/2020] [Accepted: 02/10/2020] [Indexed: 11/19/2022]
Abstract
Baleen whales are vulnerable to environmental impacts due to low fecundity, capital breeding strategies, and their reliance on a large amount of prey resources over large spatial scales. There has been growing interest in monitoring health and physiological stress in these species but, to date, few measures have been validated. The purpose of this study was to examine whether blubber cortisol could be used as a measure of physiological stress in humpback whales. Cortisol concentrations were initially compared between live, presumably 'healthy' whales (n = 187) and deceased whales (n = 35), which had died after stranding or entanglement, or washed ashore as a carcass. Deceased whales were found to have significantly higher cortisol levels (mean ± SD; 5.47 ± 4.52 ng/g) than live whales (0.51 ± 0.14 ng/g; p < 0.001), particularly for those animals that had experienced prolonged trauma (e.g. stranding) prior to death. Blubber cortisol levels in live whales were then examined for evidence of life history-related, seasonal, or sampling-related effects. Life history group and sampling-related factors, such as encounter time and the number of biopsy sampling attempts per animal, were found to be poor predictors of blubber cortisol levels in live whales. In contrast, blubber cortisol levels varied seasonally, with whales migrating north towards the breeding grounds in winter having significantly higher levels (0.54 ± 0.21 ng/g, p = 0.016) than those migrating south towards the feeding grounds in spring (0.48 ± 1.23 ng/g). These differences could be due to additional socio-physiological stress experienced by whales during peaks in breeding activity. Overall, blubber cortisol appears to be a suitable measure of chronic physiological stress in humpback whales.
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Affiliation(s)
- Fletcher M J Mingramm
- Cetacean Ecology and Acoustics Laboratory, School of Veterinary Science, The University of Queensland, Gatton, QLD 4343, Australia; Wildlife Endocrinology Lab, School of Agriculture and Food Science, The University of Queensland, Gatton, QLD 4343, Australia.
| | - Tamara Keeley
- Wildlife Endocrinology Lab, School of Agriculture and Food Science, The University of Queensland, Gatton, QLD 4343, Australia
| | - Deanne J Whitworth
- School of Veterinary Science, The University of Queensland, Gatton, QLD 4343, Australia; Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Rebecca A Dunlop
- Cetacean Ecology and Acoustics Laboratory, School of Veterinary Science, The University of Queensland, Gatton, QLD 4343, Australia
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21
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Bechshoft T, Wright AJ, Styrishave B, Houser D. Measuring and validating concentrations of steroid hormones in the skin of bottlenose dolphins ( Tursiops truncatus). CONSERVATION PHYSIOLOGY 2020; 8:coaa032. [PMID: 32431813 PMCID: PMC7221262 DOI: 10.1093/conphys/coaa032] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 02/10/2020] [Accepted: 03/20/2020] [Indexed: 05/27/2023]
Abstract
A previously published analytical method demonstrated the quantification of the hormone cortisol in cetacean skin. However, little is known about the transfer of hormones between blood and skin. Recognizing that such information is essential to effectively using skin samples within marine mammal stress research, the primary goals of this study were to (i) expand on the number of steroid hormones proved quantifiable in the cetacean skin matrix and (ii) validate the use of cetacean skin as a matrix for measuring stress-related hormones. Five adult bottlenose dolphins were subjected to an out of water stress test. Non-invasive sloughed skin samples were collected from each dolphin: once ~3 and once ~1 week prior to the stress test; at the time of the stress test; and twice weekly for 11 to 17 weeks subsequent to the stress test. LCMS/MS analysis of the samples recovered consistent data on three corticosteroids (cortisol, aldosterone, corticosterone), two androgens (testosterone, DHEA) and one progestagen (progesterone). A range of other hormones were also quantifiable, although not consistently so across samples. Results demonstrated that the hormonal response to an acute stressor could be detected in skin: the time from stress test to skin cortisol peak was an average of 46 days, whereas it was 55 days for corticosterone and 47 days for aldosterone. Results also showed that baseline hormonal concentrations were obtainable from skin samples collected during or immediately after the animals were subjected to the acute stressor. This study further develops and validates a non-invasive method for measuring cortisol and other hormones related to stress, health, and reproduction in the skin of cetaceans, potentially supporting investigations of acute and chronic stress, such as cetacean endocrine responses to distinct (e.g. naval sonar exposure) or prolonged stressors (e.g. shipping noise).
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Affiliation(s)
- Thea Bechshoft
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, P.O. Box 358, 4000 Roskilde, Denmark
| | - Andrew J Wright
- Ocean and Ecosystem Sciences Division, Maritimes Region Fisheries and Oceans Canada, Bedford Institute of Oceanography, 1 Challenger Dr., PO Box 1006, Dartmouth, NS B2Y 4A2, Canada
- Department of Environmental Science and Policy, George Mason University, 400 University Drive, Fairfax, VA 22030, USA
| | - Bjarne Styrishave
- Toxicology and Drug Metabolism Group, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen OE, Denmark
| | - Dorian Houser
- National Marine Mammal Foundation, 2240 Shelter Island Drive Suite 200, San Diego, CA 92106, USA
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22
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Studying animal niches using bulk stable isotope ratios: an updated synthesis. Oecologia 2020; 193:27-51. [DOI: 10.1007/s00442-020-04654-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 04/11/2020] [Indexed: 10/24/2022]
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23
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Galligan TM, Boggs ASP, Balmer BC, Rowles T, Smith CR, Townsend F, Wells RS, Kellar NM, Zolman ES, Schwacke LH. Blubber steroid hormone profiles as indicators of physiological state in free-ranging common bottlenose dolphins (Tursiops truncatus). Comp Biochem Physiol A Mol Integr Physiol 2019; 239:110583. [PMID: 31648064 DOI: 10.1016/j.cbpa.2019.110583] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 09/27/2019] [Accepted: 10/01/2019] [Indexed: 02/08/2023]
Abstract
Blubber has been proposed as a possible alternative to blood in the assessment of endocrine physiology in marine mammals because it can be collected via remote biopsy, which removes some of the confounding variables and logistical constraints associated with blood collection. To date, few studies have directly assessed the relationships between circulating versus blubber steroid hormone profiles in marine mammals, and these studies have been limited to a small subset of steroid hormones, which collectively limit the current utility of blubber steroid hormone measurements. In this study, we used liquid-chromatography tandem-mass spectrometry (LC-MS/MS) to screen for 16 steroid hormones in matched blood and blubber samples from free-ranging common bottlenose dolphins (Tursiops truncatus). Seven steroid hormones were detected and quantified, including two progestogens, two androgens, and three corticosteroids. Using principal components analysis (PCA), we explored relationships between hormones in both matrices and three physiological states: sexual maturity, pregnancy, and acute stress response. Plasma and blubber testosterone and its precursors, 17-hydroxyprogesterone and androstenedione, loaded to the first principal component (PC1), and PC1 scores were higher in mature males. Plasma and blubber progesterone loaded to PC2, and pregnant/probable pregnant females had significantly higher PC2 scores. Pregnant females also had higher PC1 scores than other females, suggesting differences in androgen profiles between these groups. There was disagreement between plasma and blubber corticosteroid profiles, as indicated by their loading to different PCs; plasma corticosteroids loaded to PC3 and blubber corticosteroids to PC4. PC3 scores were significantly predicted by elapsed time to blood collection (i.e., time between initiating the capture process and blood collection), while elapsed time to blubber collection significantly predicted PC4 scores, indicating that corticosteroid profiles shift in both tissues during acute stress. Corticosteroid profiles were not related to demographic group, site-month, body mass index, water temperature, or time spent outside of the water on the processing boat. Overall, these results demonstrate that blubber steroid hormone profiles reflect changes in endocrine function that occur over broad temporal scales.
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Affiliation(s)
- Thomas M Galligan
- Hollings Marine Laboratory, Medical University of South Carolina, 331 Fort Johnson Rd, Charleston, SC 29412, USA; Department of Fish and Wildlife Conservation, College of Natural Resources and the Environment, Virginia Tech, 101 Cheatham Hall, 310 West Campus Dr., Blacksburg, VA 24060, USA.
| | - Ashley S P Boggs
- National Institute of Standards and Technology, Chemical Sciences Division, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA
| | - Brian C Balmer
- National Marine Mammal Foundation, 2240 Shelter Island Drive, Suite 200, San Diego, CA 92106, USA
| | - Teri Rowles
- Office of Protected Resources, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 1315 East-West Highway, Silver Spring, MD 20910, USA
| | - Cynthia R Smith
- National Marine Mammal Foundation, 2240 Shelter Island Drive, Suite 200, San Diego, CA 92106, USA
| | - Forrest Townsend
- Bayside Hospital for Animals, 251 Racetrack Road NE, Fort Walton Beach, FL 32547, USA
| | - Randall S Wells
- Chicago Zoological Society's Sarasota Dolphin Research Program, c/o Mote Marine Laboratory, 1600 Ken Thompson Pkwy, Sarasota, FL 34236, USA
| | - Nicholas M Kellar
- Ocean Associates, Inc., under contract to the Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 4007 N Abingdon St, Arlington, VA 22207, USA
| | - Eric S Zolman
- National Marine Mammal Foundation, 2240 Shelter Island Drive, Suite 200, San Diego, CA 92106, USA
| | - Lori H Schwacke
- National Marine Mammal Foundation, 2240 Shelter Island Drive, Suite 200, San Diego, CA 92106, USA
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24
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Boggs ASP, Ragland JM, Zolman ES, Schock TB, Morey JS, Galligan TM, Dalle Luche G, Balmer BC, Wells RS, Kucklick JR, Schwacke LH. Remote blubber sampling paired with liquid chromatography tandem mass spectrometry for steroidal endocrinology in free-ranging bottlenose dolphins (Tursiops truncatus). Gen Comp Endocrinol 2019; 281:164-172. [PMID: 31199925 PMCID: PMC6990413 DOI: 10.1016/j.ygcen.2019.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 05/28/2019] [Accepted: 06/10/2019] [Indexed: 02/03/2023]
Abstract
Liquid chromatography tandem mass spectrometry allows for the measurement of steroid hormone suites in the blubber of marine mammals. By combining this technology with minimally invasive techniques such as remote biopsy, endocrine profiles can be assessed, allowing for studies of hormonal profile variation over time. In this study, we explored associations among different steroidogenic pathways and seasonal differences in blubber hormone profiles of free-ranging common bottlenose dolphins along the coast of South Carolina, USA. Male dolphins experience a peak in testosterone, androstenedione, progesterone, and 17-hydroxyprogesterone in the spring, likely related to an upregulation of the androgen steroidogenic pathway during mating season. We also observed increased cortisol concentrations during summer compared to winter. Among females, there was an increase in androstenedione with elevated progesterone concentrations indicative of pregnancy, highlighting another potential endocrine marker for pregnancy in free-ranging dolphins. This work emphasizes the importance of selecting the appropriate season for studies on endocrine status to effectively uncover physiological variation or disruption in free-ranging cetaceans.
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Affiliation(s)
- Ashley S P Boggs
- National Institute of Standards and Technology, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA.
| | - Jared M Ragland
- National Institute of Standards and Technology, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA
| | - Eric S Zolman
- National Marine Mammal Foundation, 3419 Maybank Highway, Ste B, Johns Island, SC 29455, USA
| | - Tracey B Schock
- National Institute of Standards and Technology, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA
| | - Jeanine S Morey
- National Marine Mammal Foundation, 3419 Maybank Highway, Ste B, Johns Island, SC 29455, USA
| | - Thomas M Galligan
- Medical University of South Carolina, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA; JHT, Inc. under contract to the National Oceanic and Atmospheric Administration, National Centers for Coastal Ocean Service, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA; Virginia Polytechnic Institute and State University, Department of Fish and Wildlife Conservation, 101 Cheatham Hall, 310 West Campus Drive, Blacksburg, VA 24060, USA
| | - Greta Dalle Luche
- Griffith University, Environmental Futures Research Institute, Southern Ocean Persistent Organic Pollutants Program, 170 Kessels Road, Brisbane, QLD 4111, Australia
| | - Brian C Balmer
- National Marine Mammal Foundation, 3419 Maybank Highway, Ste B, Johns Island, SC 29455, USA
| | - Randall S Wells
- Chicago Zoological Society's Sarasota Dolphin Research Program, c/o Mote Marine Laboratory, 1600 Ken Thompson Pkwy, Sarasota, FL 34236, USA
| | - John R Kucklick
- National Institute of Standards and Technology, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA
| | - Lori H Schwacke
- National Marine Mammal Foundation, 3419 Maybank Highway, Ste B, Johns Island, SC 29455, USA
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25
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Dalle Luche G, Bengtson Nash S, Kucklick JR, Mingramm FMJ, Boggs ASP. Liquid chromatography tandem mass spectrometry for the quantification of steroid hormone profiles in blubber from stranded humpback whales ( Megaptera novaeangliae). CONSERVATION PHYSIOLOGY 2019; 7:coz030. [PMID: 32742659 PMCID: PMC6664595 DOI: 10.1093/conphys/coz030] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 04/12/2019] [Accepted: 05/16/2019] [Indexed: 05/27/2023]
Abstract
Marine mammal blubber is known to have quantifiable concentrations of steroid hormones and is increasingly chosen as a matrix for the detection of these reproductive and stress biomarkers. Steroid hormones act through complex cascades, often in concert, yet studies conducted on cetaceans have rarely measured more than two steroids simultaneously. Due to the role of steroid hormones in multiple physiological processes, and variability in concentration among individuals, data on single compounds are often difficult to interpret. Here a liquid chromatography tandem mass spectrometry method for the simultaneous analyses of multiple steroid hormones in cetacean blubber was validated and applied to samples from 10 stranded humpback whales (Megaptera novaeangliae). Progesterone, 17α-hydroxyprogesterone, testosterone, androstenedione, oestrone, oestradiol, cortisone, cortisol, corticosterone and 11-deoxycorticosterone were reliably (relative standard deviation on six replicates <15%) and accurately (recovery of an amended sample between 70% and 120%) quantified, but not 11-deoxycortisol. With the exception of progesterone, testosterone, oestradiol and cortisol, these compounds were quantified for the first time in humpback whales. Given that blubber is frequently collected from free-swimming cetaceans in ongoing research programs, the technique developed here could substantially strengthen understanding and monitoring of the physiological condition of these species.
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Affiliation(s)
- Greta Dalle Luche
- Southern Ocean Persistent Organic Pollutants Program, Griffith University, Nathan, QLD, Australia
| | - Susan Bengtson Nash
- Southern Ocean Persistent Organic Pollutants Program, Griffith University, Nathan, QLD, Australia
| | - John R Kucklick
- Hollings Marine Laboratory, National Institute of Standard and Technology, Charleston, SC , USA
| | | | - Ashley S P Boggs
- Hollings Marine Laboratory, National Institute of Standard and Technology, Charleston, SC , USA
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26
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Galligan TM, Balmer BC, Schwacke LH, Bolton JL, Quigley BM, Rosel PE, Ylitalo GM, Boggs ASP. Examining the relationships between blubber steroid hormones and persistent organic pollutants in common bottlenose dolphins. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 249:982-991. [PMID: 31146318 DOI: 10.1016/j.envpol.2019.03.083] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 03/19/2019] [Accepted: 03/20/2019] [Indexed: 06/09/2023]
Abstract
Odontocete cetaceans bioaccumulate high concentrations of endocrine disrupting persistent organic pollutants (POPs), including dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyltrichloroethylene (DDE), and dichlorodiphenyldichloroethane (DDD) - collectively DDTs - but few studies have explored DDTs-mediated endocrine disruption in cetaceans. Herein, we use remotely collected blubber biopsies from common bottlenose dolphins (Tursiops truncatus) inhabiting a site with high localized DDTs contamination to study the relationships between DDTs exposure and steroid hormone homeostasis in cetaceans. We quantified blubber steroid hormone concentrations by liquid chromatography-tandem mass spectrometry and blubber POP concentrations by gas chromatography-mass spectrometry. We detected six steroid hormones in blubber, including progesterone (P4), 17-hydroxyprogesterone (17OHP4), androstenedione (AE), testosterone (T), cortisol (F), and cortisone (E). Sampled dolphins (n = 62) exhibited exposure to DDT, DDE, DDD, chlordanes (CHLDs), mirex, dieldrin, hexachlorobenzene, polychlorinated biphenyls (PCBs), and brominated diphenyl ethers (BDEs). Using principal components analysis (PCA), we determined that blubber DDTs primarily loaded to the first principal component (PC1) explaining 81.6% of the total variance in POP exposure, while the remaining POPs primarily loaded to the PC2 (10.4% of variance). PC1 scores were negatively correlated with blubber T in males and blubber F in females, suggesting that exposure to DDTs impacted androgen and corticosteroid homeostasis. These conclusions were further supported by observed negative correlations between T and o,p'-DDE, o,p'-DDD, and p,p'-DDD in males sampled in the fall, and between F and the six individual DDTs and ∑6DDTs in females. Overall, these results suggest that POP-mediated endocrine disruption may have occurred in this stock of dolphins, which could negatively impact their health and fitness. However, this study relied on uncontrolled incidental exposures, making it impossible to establish a causal relationship between DDTs exposure and endocrine effects. Importantly, this study demonstrates that remotely collected blubber biopsies are a useful matrix for studying endocrine disruption in marine mammals.
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Affiliation(s)
- Thomas M Galligan
- Medical University of South Carolina, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC, 29412, USA; Virginia Polytechnic Institute and State University, Department of Fish and Wildlife Conservation, 310 West Campus Drive, 101 Cheatham Hall, Blacksburg, VA, 24060, USA.
| | - Brian C Balmer
- National Marine Mammal Foundation, 3419 Maybank Highway, Site B, Johns Island, SC, 29455, USA
| | - Lori H Schwacke
- National Marine Mammal Foundation, 3419 Maybank Highway, Site B, Johns Island, SC, 29455, USA
| | - Jennie L Bolton
- Environmental and Fisheries Sciences Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Boulevard East, Seattle, WA, 98112, USA
| | - Brian M Quigley
- National Marine Mammal Foundation, 3419 Maybank Highway, Site B, Johns Island, SC, 29455, USA
| | - Patricia E Rosel
- National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southeast Fisheries Science Center, 646 Cajundome Boulevard, Lafayette, LA, 70506, USA
| | - Gina M Ylitalo
- Environmental and Fisheries Sciences Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Boulevard East, Seattle, WA, 98112, USA
| | - Ashley S P Boggs
- National Institute of Standards and Technology, Hollings Marine Laboratory, 331 Fort Johnson Rd, Charleston, SC, 29412, USA
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27
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Mingramm FMJ, Dunlop RA, Blyde D, Whitworth DJ, Keeley T. Evaluation of respiratory vapour and blubber samples for use in endocrine assessments of bottlenose dolphins (Tursiops spp.). Gen Comp Endocrinol 2019; 274:37-49. [PMID: 30605661 DOI: 10.1016/j.ygcen.2018.12.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 11/30/2018] [Accepted: 12/30/2018] [Indexed: 12/13/2022]
Abstract
Blubber and respiratory vapour ('blow') are now commonly used for endocrine studies on cetaceans, primarily because they can be obtained using minimally invasive methods. For many species, these samples have yet to be validated for these purposes. The objective of this study was to examine the performance of blow and blubber hormone monitoring, relative to serum hormone monitoring, for evaluating the reproductive and adrenal condition of captive bottlenose dolphins (Tursiops spp.). Eighteen bottlenose dolphins were sampled five times for serum and blow and twice for blubber throughout a one-year period. Concentrations of progesterone, testosterone, oestradiol and cortisol were measured in each sample type. Hormone levels were examined in relation to dolphin age, sex, reproductive status, season, time of sample collection (morning/afternoon) and collection type (in- or out-of-water sampling). Patterns in hormone levels were similar for serum and blubber. For instance, in both sample types, progesterone levels were significantly higher in pregnant (serum: 34.10 ± 8.64 ng/mL; blubber: 13.01 ± 0.72 ng/g) than in non-pregnant females (serum: 0.32 ± 0.09 ng/mL; blubber: 1.17 ± 0.10 ng/g). This pattern was not detected in blow, primarily because seawater contamination, nylon sampling materials and variable sample volumes influenced measured concentrations. In addition, the respiratory water content of a blow sample is known to affect measured hormone levels. Two methods were trialled to control for variability in sample volumes and dilution: (1) normalising blow hormone concentrations relative to urea nitrogen levels (a potential endogenous standard), and (2) measuring the relative proportions (i.e. ratios) of blow hormones. These correction measures had little influence on blow hormone results. Further refinement of blow hormone monitoring methods is required before they can be used for reproductive or adrenal assessments of bottlenose dolphins. Blubber, on the other hand, should be a suitable proxy for serum when attempting to classify pregnancy status and male maturity in these species.
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Affiliation(s)
- F M J Mingramm
- Cetacean Ecology and Acoustics Laboratory, School of Veterinary Science, The University of Queensland, Gatton, Queensland 4343, Australia; Wildlife Endocrinology Lab, School of Agriculture and Food Science, The University of Queensland, Gatton, Queensland 4343, Australia.
| | - R A Dunlop
- Cetacean Ecology and Acoustics Laboratory, School of Veterinary Science, The University of Queensland, Gatton, Queensland 4343, Australia
| | - D Blyde
- SeaWorld Australia, Gold Coast, Queensland 4217, Australia
| | - D J Whitworth
- School of Veterinary Science, The University of Queensland, Gatton, Queensland 4343, Australia; Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - T Keeley
- Wildlife Endocrinology Lab, School of Agriculture and Food Science, The University of Queensland, Gatton, Queensland 4343, Australia
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28
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Vail CS, Reiss D, Brakes P, Butterworth A. Potential Welfare Impacts of Chase and Capture of Small Cetaceans during Drive Hunts in Japan. J APPL ANIM WELF SCI 2019; 23:193-208. [PMID: 30806084 DOI: 10.1080/10888705.2019.1574576] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Drive hunts are a method to herd, capture and kill small cetaceans (whales and dolphins) in coastal waters of some countries including Japan and the Faroe Islands. In Japan, these methods are often associated with the acquisition of live dolphins for international marine parks and aquaria. During the hunts, dolphins are herded by a flotilla of fishing vessels and loud underwater noise created by fishermen banging hammers on metal poles. The prolonged and strenuous chase and use of sound barriers to herd, capture, and restrain the dolphins can result in acute stress and injury. The authors review physiological and behavioral data pertaining to chase, encirclement, and live capture of dolphins and draw comparisons between chase and capture data for marine and terrestrial species. This analysis raises substantial welfare concerns associated with the hunts and acquisition of dolphins from such capture operations. The authors assert that this data detailing the negative impacts of chase, herding and handling (capture) of small cetaceans renders these hunts inherently inhumane and should inform policy relating to the collection and management of dolphins in the wild.
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Affiliation(s)
| | - Diana Reiss
- Department of Psychology, Hunter College, City University of New York, New York, NY, USA
| | - Philippa Brakes
- Centre for Ecology and Conservation, University of Exeter, Tremough, Cornwall, UK.,Whale and Dolphin Conservation (WDC), Wiltshire, UK
| | - Andrew Butterworth
- Clinical Veterinary School, University of Bristol Veterinary School, Langford, UK
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Misra BB, Ruiz-Hernández IM, Hernández-Bolio GI, Hernández-Núñez E, Díaz-Gamboa R, Colli-Dula RC. 1H NMR metabolomic analysis of skin and blubber of bottlenose dolphins reveals a functional metabolic dichotomy. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2019; 30:25-32. [PMID: 30771562 DOI: 10.1016/j.cbd.2019.02.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 02/05/2019] [Accepted: 02/07/2019] [Indexed: 11/27/2022]
Abstract
The common bottlenose dolphin (Tursiops truncatus) is a carnivorous cetacean that thrives in marine environments, one of the apex predators of the marine food web. They are found in coastal and estuarine ecosystems, which are known to be sensitive to environmental impacts. Dolphins are considered sentinel organisms for monitoring the health of coastal marine ecosystems due to their role as predators that can bioaccumulate contaminants. Although recent studies have focused on capturing the circulating metabolomes of these mammals, and in the context of pollutants and exposures in the marine environment, skin and blubber are important surface and protective tissues that have not been adequately probed for metabolism. Using a proton nuclear magnetic resonance spectroscopy (1H NMR) based metabolomics approach, we quantified 51 metabolites belonging to 74 different metabolic pathways in the skin and blubber of stranded bottlenose dolphin (n = 4) samples collected at different localities in the Southern Zone coast of Yucatan Peninsula of Mexico. Results indicate that metabolism of skin and blubber are quantitatively very different. These metabolite abundances could help discriminate the tissue-types using supervised partial least square regression discriminant analysis (PLSDA). Further, using hierarchical clustering analysis and random forest analysis of the metabolite abundances, the results pointed to unique metabolites that are important classifiers of the tissue-type. On one hand, the differential metabolic patterns, mainly linking fatty acid metabolism and ketogenic amino acids, seem to constitute a characteristic of blubber, thus pointing to fat synthesis and deposition. On the other hand, the skin showed several metabolites involved in gluconeogenic pathways, pointing towards an active anabolic energy-generating metabolism. The most notable pathways found in both tissues included: urea cycle, nucleotide metabolism, amino acid metabolism, glutathione metabolism among others. Our 1H NMR metabolomics analysis allowed the quantification of metabolites associated with these two organs, i.e., pyruvic acid, arginine, ornithine, 2-hydroxybutyric acid, 3-hydroxyisobutyric acid, and acetic acid, as discriminatory and classifying metabolites. These results would lead to further understanding of the functional and physiological roles of dolphin skin and blubber metabolism for better efforts in their conservation, as well as useful target biopsy tissues for monitoring of dolphin health conditions in marine pollution and ecotoxicology studies.
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Affiliation(s)
- Biswapriya B Misra
- Center for Precision Medicine, Department of Internal Medicine, Section of Molecular Medicine, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem 27157, NC, USA
| | | | | | - Emanuel Hernández-Núñez
- Departamento de Recursos del Mar, Cinvestav Unidad Mérida, Mérida, Yucatán 97310, Mexico; Consejo Nacional de Ciencia y Tecnología (CONACYT), Mexico
| | - Raúl Díaz-Gamboa
- Universidad Autónoma de Yucatán, Campus de Ciencias Biológicas y Agropecuarias, 97100 Mérida, Yucatán, Mexico
| | - Reyna Cristina Colli-Dula
- Departamento de Recursos del Mar, Cinvestav Unidad Mérida, Mérida, Yucatán 97310, Mexico; Consejo Nacional de Ciencia y Tecnología (CONACYT), Mexico.
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Charapata P, Horstmann L, Jannasch A, Misarti N. A novel method to measure steroid hormone concentrations in walrus bone from archaeological, historical, and modern time periods using liquid chromatography/tandem mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2018; 32:1999-2023. [PMID: 30192037 PMCID: PMC6282614 DOI: 10.1002/rcm.8272] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 08/15/2018] [Accepted: 08/19/2018] [Indexed: 05/24/2023]
Abstract
RATIONALE A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was validated and utilized to measure and analyze four steroid hormones related to stress and reproduction in individual samples from a novel tissue, Pacific walrus (Odobenus rosmarus divergens, herein walrus) bone. This method determines steroid hormone concentrations in the remote walrus population over millennia from archaeological (>200 bp), historical (200-20 bp), and modern (2014-2016) time periods. METHODS Lipids were extracted from walrus bone collected from these periods using methanol before LC/MS/MS analysis. Isotopically labeled internal standards for each target hormone were added to every sample. Analytical and physiological validations were performed. Additionally, a tissue comparison was done among paired walrus bone, serum, and blubber samples. A rapid resolution liquid chromatography system coupled to a QqQ mass spectrometer was used to analyze all samples after derivatization for progesterone, testosterone, cortisol, and estradiol concentrations. Multiple reaction monitoring was used for MS analysis and data were acquired in positive electrospray ionization mode. RESULTS Progesterone, testosterone, cortisol, and estradiol were linear along their respective standard calibration curves based on their R2 values (all > 0.99). Accuracy ranged from 93-111% for all hormones. The recovery of extraction, recovery of hormones without matrix effect, was 92-101%. The overall process efficiency of our method for measuring hormones in walrus bone was 93-112%. Progesterone and testosterone concentrations were not affected by reproductive status among adult females and males, respectively. However, estradiol was different among pregnant and non-pregnant adult females. Overall, steroid hormones reflect a long-term reservoir in cortical bone. This method was also successfully applied to walrus bone as old as 3585 bp. CONCLUSIONS LC/MS/MS analysis of bone tissue (0.2-0.3 g) provides stress and reproductive data from elusive walruses that were alive thousands of years ago. Based on physiological validations, tissue comparison, and published literature, steroid hormone concentrations measured in walrus cortical bone could represent an accumulated average around a 10-20-year time span. By investigating how stress and reproductive physiology may have changed over the past ~3000 years based on bone steroid hormone concentrations, this method will help answer how physiologically resilient walruses are to climate change in the Arctic.
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Affiliation(s)
- Patrick Charapata
- College of Fisheries and Ocean SciencesUniversity of Alaska FairbanksPO Box 757220FairbanksAK99775USA
- Department of BiologyBaylor UniversityOne Bear PlaceWacoTX76706USA
| | - Lara Horstmann
- College of Fisheries and Ocean SciencesUniversity of Alaska FairbanksPO Box 757220FairbanksAK99775USA
| | - Amber Jannasch
- Bindley Bioscience CenterPurdue University1203 W State St.West LafayetteIN47906USA
| | - Nicole Misarti
- Water and Environmental Research CenterUniversity of Alaska FairbanksPO Box 755910FairbanksAK99775USA
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31
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Baleen whale cortisol levels reveal a physiological response to 20th century whaling. Nat Commun 2018; 9:4587. [PMID: 30389921 PMCID: PMC6215000 DOI: 10.1038/s41467-018-07044-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 10/09/2018] [Indexed: 01/15/2023] Open
Abstract
One of the most important challenges researchers and managers confront in conservation ecology is predicting a population's response to sub-lethal stressors. Such predictions have been particularly elusive when assessing responses of large marine mammals to past anthropogenic pressures. Recently developed techniques involving baleen whale earplugs combine age estimates with cortisol measurements to assess spatial and temporal stress/stressor relationships. Here we show a relationship between baseline-corrected cortisol levels and corresponding whaling counts of fin, humpback, and blue whales in the Northern Hemisphere spanning the 20th century. We also model the impact of alternative demographic and environmental factors and determine that increased anomalies of sea surface temperature over a 46-year mean (1970-2016) were positively associated with cortisol levels. While industrial whaling can deplete populations by direct harvest, our data underscore a widespread stress response in baleen whales that is peripheral to whaling activities or associated with other anthropogenic change.
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32
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Hamilton MT, Finger JW, Elsey RM, Mastromonaco GF, Tuberville TD. Corticosterone in American alligator (Alligator mississippiensis) tail scutes: Evaluating the feasibility of using unconventional samples for investigating environmental stressors. Gen Comp Endocrinol 2018; 268:7-13. [PMID: 30031024 DOI: 10.1016/j.ygcen.2018.07.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 06/23/2018] [Accepted: 07/13/2018] [Indexed: 12/31/2022]
Abstract
Baseline plasma corticosterone (CORT) concentrations have been widely used to investigate the effects of stressors in wild and captive crocodilians. However, collecting baseline plasma CORT samples from wild crocodilians may be particularly difficult due to the capture and handling protocols used for large individuals. Thus, it may prove beneficial to use recently modified techniques for extracting CORT deposited in keratinized and non-keratinized tissues to better quantify the effects of long-term stress in crocodilians. In this study, we investigated the feasibility of using American alligator (Alligator mississippiensis) tail scute tissues to quantify CORT by collecting blood and tail scutes from 40 alligators before and after a short-term handling stressor. The objective of the current study was to better understand CORT deposition in crocodilian scutes and whether short-term increases in CORT could be detected. We found that CORT can be reliably extracted from alligator scute tissue and quantified using a commercially available enzyme immunoassay. However, there was a significant increase in scute CORT concentrations following an alligator being exposed to a short-term stressor (p = 0.017), although the magnitude of change was less than observed in plasma samples from the same individuals (p = 0.002). Furthermore, our results indicate that there was a significant effect of body condition on an alligator's post-stressor CORT concentration (p = 0.02). While our study is among the first to experimentally examine the usefulness of tissue CORT in crocodilians, a combination of field and laboratory experiments are needed to better understand deposition rates of CORT in scute tissues and to further validate the usefulness of tissue glucocorticoids for evaluating the effects of stress.
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Affiliation(s)
- Matthew T Hamilton
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802, USA.
| | - John W Finger
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802, USA; Department of Environmental Health Science, University of Georgia, Athens, GA 30602, USA
| | - Ruth M Elsey
- Louisiana Department of Wildlife and Fisheries, Rockefeller Wildlife Refuge, Grand Chenier, LA 70643, USA
| | | | - Tracey D Tuberville
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802, USA
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33
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Champagne CD, Kellar NM, Trego ML, Delehanty B, Boonstra R, Wasser SK, Booth RK, Crocker DE, Houser DS. Comprehensive endocrine response to acute stress in the bottlenose dolphin from serum, blubber, and feces. Gen Comp Endocrinol 2018; 266:178-193. [PMID: 29852162 DOI: 10.1016/j.ygcen.2018.05.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 05/11/2018] [Accepted: 05/13/2018] [Indexed: 10/16/2022]
Abstract
Several hormones are potential indicators of stress in free-ranging animals and provide information on animal health in managed-care settings. In response to stress, glucocorticoids (GC, e.g. cortisol) first appear in circulation but are later incorporated into other tissues (e.g. adipose) or excreted in feces or urine. These alternative matrices can be sampled remotely, or by less invasive means, than required for blood collection and are especially valuable in highly mobile species, like marine mammals. We characterized the timing and magnitude of several hormones in response to a stressor in bottlenose dolphins (Tursiops truncatus) and the subsequent incorporation of cortisol into blubber, and its metabolites excreted in feces. We evaluated the endocrine response to an acute stressor in bottlenose dolphins under managed care. We used a standardized stress protocol where dolphins voluntarily beached onto a padded platform and remained out of water for two hours; during the stress test blood samples were collected every 15 min and blubber biopsies were collected every hour (0, 60, and 120 min). Each subject was studied over five days: voluntary blood samples were collected on each of two days prior to the stress test; 1 and 2 h after the conclusion of the out-of-water stress test; and on the following two days after the stress test. Fecal samples were collected daily, each afternoon. The acute stressor resulted in increases in circulating ACTH, cortisol, and aldosterone during the stress test, and each returned to baseline levels within 2 h of the dolphin's return to water. Both cortisol and aldosterone concentrations were correlated with ACTH, suggesting both corticosteroids are at least partly regulated by ACTH. Thyroid hormone concentrations were generally unaffected by the acute stressor. Blubber cortisol increased during the stress test, and fecal GC excretion was elevated on the day of the stress test. We found that GCs in bottlenose dolphins can recover within hours of acute stress, and that cortisol release can be detected in alternate matrices within a few hours-within 2 h in blubber, and 3.5-5 h in fecal samples.
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Affiliation(s)
- Cory D Champagne
- National Marine Mammal Foundation, 2240 Shelter Island Dr Suite 200, San Diego, CA 92106, United States.
| | - Nicholas M Kellar
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, NOAA, 8901 La Jolla Shores Dr, La Jolla, CA 92037, United States
| | - Marisa L Trego
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, NOAA, 8901 La Jolla Shores Dr, La Jolla, CA 92037, United States; Ocean Associates, Inc., 4007 N Abingdon St, Arlington, VA 22207, United States
| | - Brendan Delehanty
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Rudy Boonstra
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Samuel K Wasser
- Center for Conservation Biology Box 351800, University of Washington, Seattle, WA 98195, United States
| | - Rebecca K Booth
- Center for Conservation Biology Box 351800, University of Washington, Seattle, WA 98195, United States
| | - Daniel E Crocker
- Department of Biology, Sonoma State University. 1801 E. Cotati Ave, Rohnert Park, CA 94928, United States
| | - Dorian S Houser
- National Marine Mammal Foundation, 2240 Shelter Island Dr Suite 200, San Diego, CA 92106, United States
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Kershaw JL, Botting CH, Brownlow A, Hall AJ. Not just fat: investigating the proteome of cetacean blubber tissue. CONSERVATION PHYSIOLOGY 2018; 6:coy003. [PMID: 29479430 PMCID: PMC5814904 DOI: 10.1093/conphys/coy003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 12/14/2017] [Accepted: 01/24/2018] [Indexed: 06/01/2023]
Abstract
Mammalian adipose tissue is increasingly being recognized as an endocrine organ involved in the regulation of a number of metabolic processes and pathways. It responds to signals from different hormone systems and the central nervous system, and expresses a variety of protein factors with important paracrine and endocrine functions. This study presents a first step towards the systematic analysis of the protein content of cetacean adipose tissue, the blubber, in order to investigate the kinds of proteins present and their relative abundance. Full depth blubber subsamples were collected from dead-stranded harbour porpoises (Phocoena phocoena) (n = 21). Three total protein extraction methods were trialled, and the highest total protein yields with the lowest extraction variability were achieved using a RIPA cell lysis and extraction buffer based protocol. Extracted proteins were separated using 1D Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE), and identified using nanoflow Liquid Chromatography Electrospray Ionization in tandem with Mass Spectrometry (nLC-ESI-MS/MS). A range of proteins were identified (n = 295) and classed into eight functional groups, the most abundant of which were involved in cell function and metabolism (45%), immune response and inflammation (15%) and lipid metabolism (11%). These proteins likely originate both from the various cell types within the blubber tissue itself, and from the circulation. They therefore have the potential to capture information on the cellular and physiological stresses experienced by individuals at the time of sampling. The importance of this proteomic approach is two-fold: Firstly, it could help to assign novel functions to marine mammal blubber in keeping with current understanding of the multi-functional role of adipose tissue in other mammals. Secondly, it could lead to the development of a suite of biomarkers to better monitor the physiological state and health of live individuals though remote blubber biopsy sampling.
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Affiliation(s)
- Joanna L Kershaw
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews KY16 8LB, UK
| | - Catherine H Botting
- Biomedical Sciences Research Complex, School of Chemistry, Biomolecular Sciences Building Annexe, North Haugh, University of St Andrews, St Andrews KY16 9ST, UK
| | - Andrew Brownlow
- Scottish Marine Animals Strandings Scheme, SAC Consulting Veterinary Services, Inverness IV2 5NA, UK
| | - Ailsa J Hall
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews KY16 8LB, UK
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Galligan TM, Schwacke LH, McFee WE, Boggs ASP. Evidence for cortisol-cortisone metabolism by marine mammal blubber. MARINE BIOLOGY 2018; 165:10.1007/s00227-018-3373-4. [PMID: 31579267 PMCID: PMC6774200 DOI: 10.1007/s00227-018-3373-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 06/11/2018] [Indexed: 05/06/2023]
Abstract
Blubber, a specialized hyperdermic adipose tissue found in marine mammals, has been identified as a useful tissue for the assessment of steroid hormone homeostasis in cetaceans. However, blubber cortisol measurements are not quantitatively predictive of circulating cortisol concentrations in bottlenose dolphins. In other mammals, adipose tissue metabolizes steroid hormones. Thus, it is proposed that the disagreement between blubber and blood cortisol in bottlenose dolphins could be due in part to metabolism of corticosteroids in blubber. The purpose of this study is to characterize the ability of blubber to interconvert cortisol and cortisone using an in vitro design. Results demonstrate that bottlenose dolphin blubber microsomes interconvert cortisol and cortisone, an effect that is abated by denaturing the microsomes, indicating this is an enzymatic process. These findings lead to the conclusion that blubber is likely a site of active steroid metabolism, which should be considered in future studies utilizing blubber as a matrix for endocrine assessment.
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Affiliation(s)
- Thomas M. Galligan
- College of Graduate Studies, Medical University of South Carolina, 331 Fort Johnson Road, Charleston, SC 29412, USA
- JHT, Inc. Under Contract to the National Oceanic and Atmospheric Administration, National Centers for Coastal Ocean Science, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA
- Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University, 310 West Campus Drive, Cheatham Hall Rm 101, Blacksburg 24060, VA, USA
| | - Lori H. Schwacke
- National Marine Mammal Foundation, 2240 Shelter Island Drive Suite 200, San Diego, CA 92106, USA
| | - Wayne E. McFee
- National Oceanic and Atmospheric Administration, National Ocean Service, Center for Coastal Environmental Health and Biomolecular Research, 219 Fort Johnson Road, Charleston 29412, SC, USA
| | - Ashley S. P. Boggs
- National Institute of Standards and Technology, Chemical Sciences Division, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA
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36
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Rolland RM, McLellan WA, Moore MJ, Harms CA, Burgess EA, Hunt KE. Fecal glucocorticoids and anthropogenic injury and mortality in North Atlantic right whales Eubalaena glacialis. ENDANGER SPECIES RES 2017. [DOI: 10.3354/esr00866] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Beaulieu-McCoy NE, Sherman KK, Trego ML, Crocker DE, Kellar NM. Initial validation of blubber cortisol and progesterone as indicators of stress response and maturity in an otariid; the California sea lion (Zalophus californianus). Gen Comp Endocrinol 2017; 252:1-11. [PMID: 28690049 DOI: 10.1016/j.ygcen.2017.07.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 07/05/2017] [Accepted: 07/05/2017] [Indexed: 10/19/2022]
Abstract
Chronic stress can have detrimental effects on an individual's health and reproductive success. The use of cortisol quantification as an indicator of stress in free-ranging cetaceans and phocids is increasing but no studies have applied this technique on blubber in otariids. We measured cortisol concentrations in blubber samples obtained from California sea lions, Zalophus californianus, stranded in San Diego County and those incidentally killed in the California drift gillnet fishery. We also measured progesterone concentrations to assess female reproductive status and, in males, as a potential secondary measure of adrenal steroid production. Blubber cortisol and progesterone values were compared across demographic groups (sex and maturity), season, and proportion blubber lipid extracted. Stranded animals (247.3±70.767SEng/gblubber) had significantly higher cortisol concentrations compared to fishery bycaught (8.1±2.108SEng/gblubber) animals. These findings are likely driven by inherent differences in the cause of death and associated nutritional state coupled with the mean duration of expiration for these two groups of animals (i.e., the duration from an animal's initial perception of the threat-to-self until death). The duration of transition from healthy state to death in stranded animals is on the order of many hours to weeks while in fishery bycaught animals, this transition occurs much more rapidly (i.e., seconds to tens of minutes). The presumed longer duration of the mortality event in stranded animals gives sufficient time for elevated cortisol to diffuse into the blubber. No significant differences between demographic groups, or season were found. However, blubber cortisol declined inversely with proportion blubber lipid extracted, suggesting utility in assessing long-term nutritional status. Blubber progesterone was significantly higher in mature females than immature females (153.8±54.546SEng/gblubber and 9.7±3.60SEng/gblubber respectively), containing on average 15 times more progesterone, irrespective of pregnancy state. Additionally, a significant relationship between mean cortisol and progesterone was found in males with >35% blubber lipid (p<0.0001). This study is an initial step in validating blubber cortisol and progesterone concentrations as a potential marker of stress response and reproductive state, respectively, in otariids. Especially when paired with dart biopsying, this approach could represent a relatively rapid way to assess baseline stress, nutritional status and reproductive states in otariids while minimizing the effects of sampling.
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Affiliation(s)
| | | | - Marisa L Trego
- Ocean Associates Inc, 4007N. Abingdon St, Arlington, VA 22207, USA
| | - Daniel E Crocker
- Department of Biology, Sonoma State University, Rohnert Park, CA, USA
| | - Nicholas M Kellar
- Marine Mammal and Sea Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 8901 La Jolla Shores Dr, La Jolla, CA 92037, USA.
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38
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Hayden M, Bhawal R, Escobedo J, Harmon C, O'Hara TM, Klein D, San-Francisco S, Zabet-Moghaddam M, Godard-Codding CAJ. Nanospray liquid chromatography/tandem mass spectrometry analysis of steroids from gray whale blubber. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2017; 31:1088-1094. [PMID: 28423207 DOI: 10.1002/rcm.7884] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 04/11/2017] [Accepted: 04/12/2017] [Indexed: 06/07/2023]
Abstract
RATIONALE Analysis of steroids from precious blubber biopsies obtained from marine mammals, especially endangered species, can provide valuable information on their endocrine status. Challenges with currently used ELISA methodology include lack of absolute quantitation and incompatibility with multiple steroids analysis due to limited biopsy mass. Development of a sensitive, accurate analytical method for this purpose is critical. METHODS A nanospray liquid chromatography/tandem mass spectrometry (nanoLC/MS/MS) method was validated for sensitive, specific and quantitative analysis of three steroid hormones, without derivatization, extracted from 50 mg blubber samples. Data was acquired with an LTQ XL ion trap mass spectrometer in positive ion mode, using single reaction monitoring. All three steroids were analyzed in a single run. Cholic acid was used as a surrogate internal standard for quantitation due to its steroidal structure and lack of measurable endogenous levels in blubber. RESULTS The lowest limits of quantitation for progesterone, testosterone, and hydrocortisone were significantly improved compared to previous studies using conventional LC/MS/MS. The lowest limit of detection was 7 fg/μL using a 1 μL injection volume. Calibration curves for steroid quantification showed good linearity (r2 >0.99) between 14 and 3620 fg/μL, and accuracy was <20% for interday and <10% for intraday. After validation, the method was successfully applied to quantification of steroids in gray whale blubber samples. CONCLUSIONS The nanoLC/MS/MS method is more sensitive than traditional LC/MS/MS for steroid analysis. It is also compatible with other important biopsy analyses due to its small blubber mass requirement. This will benefit the reproductive and stress assessments for all marine mammals, particularly endangered populations. Copyright © 2017 John Wiley & Sons, Ltd.
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Affiliation(s)
- Mary Hayden
- The Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX, USA
| | - Ruchika Bhawal
- Center for Biotechnology and Genomics, Texas Tech University, Lubbock, TX, USA
| | - John Escobedo
- Center for Biotechnology and Genomics, Texas Tech University, Lubbock, TX, USA
| | - Clinton Harmon
- Center for Biotechnology and Genomics, Texas Tech University, Lubbock, TX, USA
| | - Todd M O'Hara
- Department of Veterinary Medicine, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - David Klein
- The Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX, USA
| | - Susan San-Francisco
- Center for Biotechnology and Genomics, Texas Tech University, Lubbock, TX, USA
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Boggs ASP, Schock TB, Schwacke LH, Galligan TM, Morey JS, McFee WE, Kucklick JR. Rapid and reliable steroid hormone profiling in Tursiops truncatus blubber using liquid chromatography tandem mass spectrometry (LC-MS/MS). Anal Bioanal Chem 2017. [PMID: 28631158 DOI: 10.1007/s00216-017-0446-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Monitoring of marine mammal steroid hormone status using matrices alternative to blood is desirable due to the ability to remotely collect samples, which minimizes stress to the animal. However, measurement techniques in alternative matrices such as blubber described to date are limited in the number and types of hormones measured. Therefore, a new method using bead homogenization to QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction, C18 post extraction cleanup and analysis by liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed and applied to the measurement of hormone suites in bottlenose dolphin blubber. Validations were conducted in blubber from fresh dead stranded bottlenose dolphin. The final method consisting of two LC separations and garnet bead homogenization was tested for extraction efficiencies. Steroids were separated using a biphenyl column for reproductive hormones and C18 column for corticosteroids. Three hormones previously noted in blubber, testosterone, progesterone, and cortisol, were quantified in addition to previously unmeasured androstenedione, 17-hydroxyprogesterone, 11-deoxycortisol, 11-deoxycorticosterone, and cortisone in a single sample (0.4 g blubber). Extraction efficiencies of all hormones from blubber ranged from 84% to 112% and all RSDs were comparable to those reported using immunoassay methods (< 15%). The method was successfully applied to remote biopsied blubber samples to measure baseline hormone concentrations. Through this method, increased coverage of steroid hormone pathways from a single remotely collected sample potentially enhances the ability to interpret biological phenomena such as reproduction and stress in wild dolphin populations. Graphical abstract The steroid hormone profile is quantifiable from a single sample of bottlenose dolphin blubber using liquid chromatography tandem mass spectrometry. This profile can be applied to remotely collected dart biopsies and be used to determine reproductive or stress status of a wild-living dolphin.
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Affiliation(s)
- Ashley S P Boggs
- National Institute of Standards and Technology, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC, 29412, USA.
| | - Tracey B Schock
- National Institute of Standards and Technology, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC, 29412, USA
| | - Lori H Schwacke
- National Oceanic and Atmospheric Administration, National Centers for Coastal Ocean Science, 219 Fort Johnson Rd, Charleston, SC, 29412, USA.,National Marine Mammal Foundation, Charleston, SC, 29412, USA
| | - Thomas M Galligan
- College of Graduate Studies, Medical University of South Carolina, 68 President Street, Charleston, SC, 29425, USA.,JHT, Inc. under contract to National Oceanic and Atmospheric Administration, National Centers for Coastal Ocean Science, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC, 29412, USA
| | - Jeanine S Morey
- JHT, Inc. under contract to National Oceanic and Atmospheric Administration, National Centers for Coastal Ocean Science, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC, 29412, USA
| | - Wayne E McFee
- National Oceanic and Atmospheric Administration, National Centers for Coastal Ocean Science, 219 Fort Johnson Rd, Charleston, SC, 29412, USA
| | - John R Kucklick
- National Institute of Standards and Technology, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC, 29412, USA
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Kershaw JL, Sherrill M, Davison NJ, Brownlow A, Hall AJ. Evaluating morphometric and metabolic markers of body condition in a small cetacean, the harbor porpoise ( Phocoena phocoena). Ecol Evol 2017; 7:3494-3506. [PMID: 28515885 PMCID: PMC5433969 DOI: 10.1002/ece3.2891] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 02/08/2017] [Accepted: 02/13/2017] [Indexed: 12/31/2022] Open
Abstract
Mammalian body condition is an important individual fitness metric as it affects both survival and reproductive success. The ability to accurately measure condition has key implications for predicting individual and population health, and therefore monitoring the population‐level effects of changing environments. No consensus currently exists on the best measure to quantitatively estimate body condition in many species, including cetaceans. Here, two measures of body condition were investigated in the harbor porpoise (Phocoena phocoena). First, the most informative morphometric body condition index was identified. The mass/length2 ratio was the most appropriate morphometric index of 10 indices tested, explaining 50% of the variation in condition in stranded, male porpoises with different causes of death and across age classes (n = 291). Mass/length2 was then used to evaluate a second measure, blubber cortisol concentration, as a metabolic condition marker. Cortisol is the main glucocorticoid hormone involved in the regulation of lipolysis and overall energy balance in mammals, and concentrations could provide information on physiological state. Blubber cortisol concentrations did not significantly vary around the girth (n = 20), but there was significant vertical stratification through the blubber depth with highest concentrations in the innermost layer. Concentrations in the dorsal, outermost layer were representative of concentrations through the full blubber depth, showed variation by sex and age class, and were negatively correlated with mass/length2. Using this species as a model for live cetaceans from which standard morphometric measurements cannot be taken, but from which blubber biopsy samples are routinely collected, cortisol concentrations in the dorsal, outermost blubber layer could potentially be used as a biomarker of condition in free‐ranging animals.
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Affiliation(s)
- Joanna L Kershaw
- Sea Mammal Research Unit Scottish Oceans Institute University of St Andrews St Andrews Fife UK
| | - Meredith Sherrill
- Sea Mammal Research Unit Scottish Oceans Institute University of St Andrews St Andrews Fife UK
| | - Nicholas J Davison
- Scottish Marine Animal Stranding Scheme SAC Veterinary Services Drummondhill Inverness UK
| | - Andrew Brownlow
- Scottish Marine Animal Stranding Scheme SAC Veterinary Services Drummondhill Inverness UK
| | - Ailsa J Hall
- Sea Mammal Research Unit Scottish Oceans Institute University of St Andrews St Andrews Fife UK
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Monreal-Pawlowsky T, Carbajal A, Tallo-Parra O, Sabés-Alsina M, Monclús L, Almunia J, Fernández-Bellon H, Lopez-Bejar M. Daily salivary cortisol levels in response to stress factors in captive common bottlenose dolphins ( Tursiops truncatus): a potential welfare indicator. Vet Rec 2017; 180:593. [PMID: 28348143 DOI: 10.1136/vr.103854] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/04/2017] [Indexed: 11/04/2022]
Affiliation(s)
- T Monreal-Pawlowsky
- Parc Zoològic de Barcelona, Parc de la Ciutadella s/n, Barcelona 08003, Spain
| | - A Carbajal
- Department of Animal Health and Anatomy, Veterinary Faculty, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - O Tallo-Parra
- Department of Animal Health and Anatomy, Veterinary Faculty, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - M Sabés-Alsina
- Department of Animal Health and Anatomy, Veterinary Faculty, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - L Monclús
- Department of Animal Health and Anatomy, Veterinary Faculty, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - J Almunia
- Loro Parque Fundación, Avda. Loro Parque, s/n., Puerto de la Cruz 38400, Spain
| | - H Fernández-Bellon
- Parc Zoològic de Barcelona, Parc de la Ciutadella s/n, Barcelona 08003, Spain
| | - M Lopez-Bejar
- Department of Animal Health and Anatomy, Veterinary Faculty, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
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Kellar NM, Speakman TR, Smith CR, Lane SM, Balmer BC, Trego ML, Catelani KN, Robbins MN, Allen CD, Wells RS, Zolman ES, Rowles TK, Schwacke LH. Low reproductive success rates of common bottlenose dolphins Tursiops truncatus in the northern Gulf of Mexico following the Deepwater Horizon disaster (2010-2015). ENDANGER SPECIES RES 2017. [DOI: 10.3354/esr00775] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Kershaw JL, Hall AJ. Seasonal variation in harbour seal (Phoca vitulina) blubber cortisol - A novel indicator of physiological state? Sci Rep 2016; 6:21889. [PMID: 26906193 PMCID: PMC4764809 DOI: 10.1038/srep21889] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 02/03/2016] [Indexed: 01/07/2023] Open
Abstract
Cortisol is one of the main glucocorticoid hormones involved in both the mammalian stress response, and in fat metabolism and energy regulation, making it of increasing interest as a biomarker for stress, health and overall physiological state. However, transient stress responses to animal handling and sampling may be important sources of measurement artefact when investigating circulating concentrations of this hormone in wildlife. Here, cortisol concentrations were measured in the plasma and, for the first time, in the blubber of live captured adult harbour seals (Phoca vitulina). Plasma cortisol concentrations were positively correlated with capture time, suggesting that they were largely driven by a stress response to the capture event. In contrast, blubber cortisol concentrations were shown not to be significantly affected by capture time and varied significantly by sex and by season, with higher concentrations during natural fasting periods of their life cycle, particularly during the moult. These results suggest that cortisol may play a key role in increased fat metabolism during highly energetically demanding periods, and that blubber concentrations have the potential to be used as physiological state indicators in phocid seals.
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Affiliation(s)
- Joanna L Kershaw
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife. KY16 8LB, UK
| | - Ailsa J Hall
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife. KY16 8LB, UK
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Clark CT, Fleming AH, Calambokidis J, Kellar NM, Allen CD, Catelani KN, Robbins M, Beaulieu NE, Steel D, Harvey JT. Heavy with child? Pregnancy status and stable isotope ratios as determined from biopsies of humpback whales. CONSERVATION PHYSIOLOGY 2016; 4:1-13. [PMID: 27766149 PMCID: PMC5070529 DOI: 10.1093/conphys/cow050] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 09/16/2016] [Accepted: 09/30/2016] [Indexed: 05/03/2023]
Abstract
Understanding reproductive rates of wild animal populations is crucially important for management and conservation. Assessing pregnancy status of free-ranging cetaceans has historically been difficult; however, recent advances in analytical techniques have allowed the diagnosis of pregnancy from small samples of blubber tissue. The primary objectives of this study were as follows: (i) to test the efficacy of blubber progesterone assays as a tool for diagnosing pregnancy in humpback whales (Megaptera novaeangliae); (ii) to estimate the pregnancy rate of humpback whales in Monterey Bay, California; and (iii) to investigate the relationship between stable isotopes and reproductive status of these whales. Progesterone concentrations of female whales fell into two distinct groups, allowing for diagnostic separation of pregnant and non-pregnant individuals. Pregnancy rate varied between years of the study (48.4%% in 2011 and 18.5% in 2012), but fell within the range of other estimates of reproductive success for this population. Stable carbon and nitrogen isotope ratios were examined to investigate the impacts of pregnancy on these values. Neither δ15N nor δ13C varied in a consistent way among animals of different sex or reproductive status. The relationship between δ15N and δ13C was strongly positive for male and non-pregnant female humpbacks; however, no relationship existed for pregnant whales. This difference may be indicative of the effects of pregnancy on δ15N, resulting from tissue synthesis and reduced excretion of nitrogenous waste, as well as on δ13C through increased mobilization of lipid stores to meet the energetic demands of pregnancy. Ultimately, our results support the use of blubber progesterone assays for diagnosing pregnancy in humpback whales and indicate that, when paired with other approaches (e.g. stable isotope analysis), pregnancy status can be an informative tool for addressing questions about animal physiology, ecology and population biology. This information will provide for more effective management and conservation efforts in a rapidly changing world.
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Affiliation(s)
- Casey T. Clark
- Moss Landing Marine Laboratories, Moss Landing, CA 95039, USA
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
- Corresponding author:College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, AK 99775, USA. Tel: +1 907 474-7824.
| | - Alyson H. Fleming
- Department of Paleobiology and Vertebrate Zoology, National Museum of Natural History Smithsonian Institution, Washington, DC 20013, USA
| | | | - Nicholas M. Kellar
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA 92037, USA
| | - Camryn D. Allen
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA 92037, USA
| | - Krista N. Catelani
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA 92037, USA
| | - Michelle Robbins
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA 92037, USA
| | - Nicole E. Beaulieu
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA 92037, USA
| | - Debbie Steel
- Marine Mammal Institute and Department of Fisheries and Wildlife, Oregon State University, Newport, OR 97365, USA
| | - James T. Harvey
- Moss Landing Marine Laboratories, Moss Landing, CA 95039, USA
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Allen CD, Robbins MN, Eguchi T, Owens DW, Meylan AB, Meylan PA, Kellar NM, Schwenter JA, Nollens HH, LeRoux RA, Dutton PH, Seminoff JA. First Assessment of the Sex Ratio for an East Pacific Green Sea Turtle Foraging Aggregation: Validation and Application of a Testosterone ELISA. PLoS One 2015; 10:e0138861. [PMID: 26465620 PMCID: PMC4605721 DOI: 10.1371/journal.pone.0138861] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 09/04/2015] [Indexed: 11/18/2022] Open
Abstract
Determining sex ratios of endangered populations is important for wildlife management, particularly species subject to sex-specific threats or that exhibit temperature-dependent sex determination. Sea turtle sex is determined by incubation temperature and individuals lack external sex-based traits until sexual maturity. Previous research utilized serum/plasma testosterone radioimmunoassays (RIA) to determine sex in immature/juvenile sea turtles. However, there has been a growing application of enzyme-linked immunosorbent assay (ELISA) for wildlife endocrinology studies, but no study on sea turtles has compared the results of ELISA and RIA. This study provides the first sex ratio for a threatened East Pacific green sea turtle (Chelonia mydas) foraging aggregation, a critical step for future management of this species. Here, we validate a testosterone ELISA and compare results between RIA and ELISA of duplicate samples. The ELISA demonstrated excellent correspondence with the RIA for providing testosterone concentrations for sex determination. Neither assay proved reliable for predicting the sex of reproductively active females with increased testosterone production. We then applied ELISA to examine the sex ratio of 69 green turtles foraging in San Diego Bay, California. Of 45 immature turtles sampled, sex could not be determined for three turtles because testosterone concentrations fell between the ranges for either sex (females: 4.1–113.1 pg/mL, males: 198.4–2,613.0 pg/mL) and these turtles were not subsequently recaptured to enable sex determination; using a Bayesian model to predict probabilities of turtle sex we predicted all three ‘unknowns’ were female (> 0.86). Additionally, the model assigned all turtles with their correct sex (if determined at recapture) with 100% accuracy. Results indicated a female bias (2.83F:1M) among all turtles in the aggregation; when focusing only on putative immature turtles the sex ratio was 3.5F:1M. With appropriate validation, ELISA sexing could be applied to other sea turtle species, and serve as a crucial conservation tool.
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Affiliation(s)
- Camryn D. Allen
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, United States of America
- * E-mail:
| | - Michelle N. Robbins
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, United States of America
| | - Tomoharu Eguchi
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, United States of America
| | - David W. Owens
- Grice Marine Lab, University of Charleston South Carolina, Charleston, South Carolina, United States of America
| | - Anne B. Meylan
- Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, St. Petersburg, Florida, United States of America
| | - Peter A. Meylan
- Natural Sciences, Eckerd College, St. Petersburg, Florida, United States of America
| | - Nicholas M. Kellar
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, United States of America
| | - Jeffrey A. Schwenter
- Grice Marine Lab, University of Charleston South Carolina, Charleston, South Carolina, United States of America
| | - Hendrik H. Nollens
- Veterinary Services, SeaWorld San Diego, San Diego, California, United States of America
| | - Robin A. LeRoux
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, United States of America
| | - Peter H. Dutton
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, United States of America
| | - Jeffrey A. Seminoff
- Marine Mammal and Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, United States of America
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